// SPDX-License-Identifier: MIT

pragma solidity >=0.6.2 <0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../../utils/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_) public {
        _name = name_;
        _symbol = symbol_;
        _decimals = 18;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal virtual {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.6.12;
pragma experimental ABIEncoderV2;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";


contract MasterChefV2 is Ownable, ReentrancyGuard{
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    struct UserInfo {
        uint256 amount;
        uint256 rewardDebt;
        uint256 boostMultiplier;
    }

    IERC20 public immutable DACKIE;

    /// @notice The only address can withdraw all the burn DACKIE.
    address public burnAdmin;

    /// @notice The contract handles the share boosts.
    address public boostContract;

    struct PoolInfo {
        uint256 accCakePerShare;
        uint256 lastRewardBlock;
        uint256 allocPoint;
        uint256 totalBoostedShare;
        bool isRegular;
    }

    /// @notice Info of each MCV2 pool.
    PoolInfo[] public poolInfo;

    IERC20[] public lpToken;

    // @notice Info of each pool user.
    mapping(uint256 => mapping(address => UserInfo)) public userInfo;
    /// @notice The whitelist of addresses allowed to deposit in special pools.
    mapping(address => bool) public whiteList;

    /// @notice Total regular allocation points. Must be the sum of all regular pools' allocation points.
    uint256 public totalRegularAllocPoint;
    /// @notice Total special allocation points. Must be the sum of all special pools' allocation points.
    uint256 public totalSpecialAllocPoint;

    uint256 public MASTERCHEF_CAKE_PER_BLOCK = 15 * 1e18;
    uint256 public constant ACC_CAKE_PRECISION = 1e18;

    /// @notice Basic boost factor, none boosted user's boost factor
    uint256 public constant BOOST_PRECISION = 100 * 1e10;
    /// @notice Hard limit for maximum boost factor, it must greater than BOOST_PRECISION
    uint256 public constant MAX_BOOST_PRECISION = 200 * 1e10;
    /// @notice total dackie rate = toBurn + toRegular + toSpecial
    uint256 public constant CAKE_RATE_TOTAL_PRECISION = 1e12;

    /// @notice The last block number of DACKIE burn action being executed.
    /// @notice DACKIE distribute % for burn
    uint256 public cakeRateToBurn = 0;
    /// @notice DACKIE distribute % for regular farm pool
    uint256 public cakeRateToRegularFarm = 1153846153846;
    /// @notice DACKIE distribute % for special pools
    uint256 public cakeRateToSpecialFarm = 46153846154;
    /// @notice DACKIE reserve
    uint256 public cakeRateReserve = 0;

    uint256 public lastBurnedBlock;

    event AddPool(uint256 indexed pid, uint256 allocPoint, IERC20 indexed lpToken, bool isRegular);
    event SetPool(uint256 indexed pid, uint256 allocPoint);
    event UpdatePool(uint256 indexed pid, uint256 lastRewardBlock, uint256 lpSupply, uint256 accCakePerShare);
    event Deposit(address indexed user, uint256 indexed pid, uint256 amount);
    event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);
    event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);

    event UpdateDackieRate(uint256 burnRate, uint256 regularFarmRate, uint256 specialFarmRate, uint256 reserveRate);
    event UpdateBurnAdmin(address indexed oldAdmin, address indexed newAdmin);
    event UpdateWhiteList(address indexed user, bool isValid);
    event UpdateBoostContract(address indexed boostContract);
    event UpdateBoostMultiplier(address indexed user, uint256 pid, uint256 oldMultiplier, uint256 newMultiplier);
    event NewDackiePerBlock(uint256 _dackiePerBlock);
    event WithdrawToken(address indexed token, address indexed to, uint256 amount);

    constructor(
        IERC20 _DACKIE,
        address _burnAdmin
    ) public {
        DACKIE = _DACKIE;
        burnAdmin = _burnAdmin;
    }

    /**
     * @dev Throws if caller is not the boost contract.
     */
    modifier onlyBoostContract() {
        require(boostContract == msg.sender, "Ownable: caller is not the boost contract");
        _;
    }

    /// @notice Returns the number of MCV2 pools.
    function poolLength() public view returns (uint256 pools) {
        pools = poolInfo.length;
    }

    /// @notice Add a new pool. Can only be called by the owner.
    /// DO NOT add the same LP token more than once. Rewards will be messed up if you do.
    /// @param _allocPoint Number of allocation points for the new pool.
    /// @param _lpToken Address of the LP ERC-20 token.
    /// @param _isRegular Whether the pool is regular or special. LP farms are always "regular". "Special" pools are only for DACKIE distributions within DackieSwap products.
    /// @param _withUpdate Whether call "massUpdatePools" operation.
    function add(
        uint256 _allocPoint,
        IERC20 _lpToken,
        bool _isRegular,
        bool _withUpdate
    ) external onlyOwner {
        require(_lpToken.balanceOf(address(this)) >= 0, "None ERC20 tokens");
        // stake DACKIE token will cause staked token and reward token mixed up,
        // may cause staked tokens withdraw as reward token,never do it.
        require(_lpToken != DACKIE, "DACKIE token can't be added to farm pools");

        if (_withUpdate) {
            massUpdatePools();
        }

        if (_isRegular) {
            totalRegularAllocPoint = totalRegularAllocPoint.add(_allocPoint);
        } else {
            totalSpecialAllocPoint = totalSpecialAllocPoint.add(_allocPoint);
        }
        lpToken.push(_lpToken);

        poolInfo.push(
            PoolInfo({
                allocPoint: _allocPoint,
                lastRewardBlock: block.number,
                accCakePerShare: 0,
                isRegular: _isRegular,
                totalBoostedShare: 0
            })
        );
        emit AddPool(lpToken.length.sub(1), _allocPoint, _lpToken, _isRegular);
    }

    /// @notice Update the given pool's DACKIE allocation point. Can only be called by the owner.
    /// @param _pid The id of the pool. See `poolInfo`.
    /// @param _allocPoint New number of allocation points for the pool.
    /// @param _withUpdate Whether call "massUpdatePools" operation.
    function set(
        uint256 _pid,
        uint256 _allocPoint,
        bool _withUpdate
    ) external onlyOwner {
        // No matter _withUpdate is true or false, we need to execute updatePool once before set the pool parameters.
        updatePool(_pid);

        if (_withUpdate) {
            massUpdatePools();
        }

        if (poolInfo[_pid].isRegular) {
            totalRegularAllocPoint = totalRegularAllocPoint.sub(poolInfo[_pid].allocPoint).add(_allocPoint);
        } else {
            totalSpecialAllocPoint = totalSpecialAllocPoint.sub(poolInfo[_pid].allocPoint).add(_allocPoint);
        }
        poolInfo[_pid].allocPoint = _allocPoint;
        emit SetPool(_pid, _allocPoint);
    }

    /// @notice Update dackie reward for all the active pools. Be careful of gas spending!
    function massUpdatePools() public {
        uint256 length = poolInfo.length;
        for (uint256 pid = 0; pid < length; ++pid) {
            PoolInfo memory pool = poolInfo[pid];
            if (pool.allocPoint != 0) {
                updatePool(pid);
            }
        }
    }

    /// @notice Update reward variables for the given pool.
    /// @param _pid The id of the pool. See `poolInfo`.
    /// @return pool Returns the pool that was updated.
    function updatePool(uint256 _pid) public returns (PoolInfo memory pool) {
        pool = poolInfo[_pid];
        if (block.number > pool.lastRewardBlock) {
            uint256 lpSupply = pool.totalBoostedShare;
            uint256 totalAllocPoint = (pool.isRegular ? totalRegularAllocPoint : totalSpecialAllocPoint);

            if (lpSupply > 0 && totalAllocPoint > 0) {
                uint256 multiplier = block.number.sub(pool.lastRewardBlock);
                uint256 cakeReward = multiplier.mul(cakePerBlock(pool.isRegular)).mul(pool.allocPoint).div(
                    totalAllocPoint
                );
                pool.accCakePerShare = pool.accCakePerShare.add((cakeReward.mul(ACC_CAKE_PRECISION).div(lpSupply)));
            }
            pool.lastRewardBlock = block.number;
            poolInfo[_pid] = pool;
            emit UpdatePool(_pid, pool.lastRewardBlock, lpSupply, pool.accCakePerShare);
        }
    }

    /// @notice Calculates and returns the `amount` of DACKIE per block.
    /// @param _isRegular If the pool belongs to regular or special.
    function cakePerBlock(bool _isRegular) public view returns (uint256 amount) {
        if (_isRegular) {
            amount = MASTERCHEF_CAKE_PER_BLOCK.mul(cakeRateToRegularFarm).div(CAKE_RATE_TOTAL_PRECISION);
        } else {
            amount = MASTERCHEF_CAKE_PER_BLOCK.mul(cakeRateToSpecialFarm).div(CAKE_RATE_TOTAL_PRECISION);
        }
    }

    /// @notice Calculates and returns the `amount` of DACKIE per block to burn.
    function cakePerBlockToBurn() public view returns (uint256 amount) {
        amount = MASTERCHEF_CAKE_PER_BLOCK.mul(cakeRateToBurn).div(CAKE_RATE_TOTAL_PRECISION);
    }

    /// @notice View function for checking pending DACKIE rewards.
    /// @param _pid The id of the pool. See `poolInfo`.
    /// @param _user Address of the user.
    function pendingCake(uint256 _pid, address _user) external view returns (uint256) {
        PoolInfo memory pool = poolInfo[_pid];
        UserInfo memory user = userInfo[_pid][_user];
        uint256 accCakePerShare = pool.accCakePerShare;
        uint256 lpSupply = pool.totalBoostedShare;

        if (block.number > pool.lastRewardBlock && lpSupply != 0) {
            uint256 multiplier = block.number.sub(pool.lastRewardBlock);

            uint256 cakeReward = multiplier.mul(cakePerBlock(pool.isRegular)).mul(pool.allocPoint).div(
                (pool.isRegular ? totalRegularAllocPoint : totalSpecialAllocPoint)
            );
            accCakePerShare = accCakePerShare.add(cakeReward.mul(ACC_CAKE_PRECISION).div(lpSupply));
        }

        uint256 boostedAmount = user.amount.mul(getBoostMultiplier(_user, _pid)).div(BOOST_PRECISION);
        return boostedAmount.mul(accCakePerShare).div(ACC_CAKE_PRECISION).sub(user.rewardDebt);
    }

    /// @notice Deposit LP tokens to pool.
    /// @param _pid The id of the pool. See `poolInfo`.
    /// @param _amount Amount of LP tokens to deposit.
    function deposit(uint256 _pid, uint256 _amount) external nonReentrant {
        PoolInfo memory pool = updatePool(_pid);
        UserInfo storage user = userInfo[_pid][msg.sender];

        require(
            pool.isRegular || whiteList[msg.sender],
            "MasterChefV2: The address is not available to deposit in this pool"
        );

        uint256 multiplier = getBoostMultiplier(msg.sender, _pid);

        if (user.amount > 0) {
            settlePendingCake(msg.sender, _pid, multiplier);
        }

        if (_amount > 0) {
            uint256 before = lpToken[_pid].balanceOf(address(this));
            lpToken[_pid].safeTransferFrom(msg.sender, address(this), _amount);
            _amount = lpToken[_pid].balanceOf(address(this)).sub(before);
            user.amount = user.amount.add(_amount);

            // Update total boosted share.
            pool.totalBoostedShare = pool.totalBoostedShare.add(_amount.mul(multiplier).div(BOOST_PRECISION));
        }

        user.rewardDebt = user.amount.mul(multiplier).div(BOOST_PRECISION).mul(pool.accCakePerShare).div(
            ACC_CAKE_PRECISION
        );
        poolInfo[_pid] = pool;

        emit Deposit(msg.sender, _pid, _amount);
    }

    /// @notice Withdraw LP tokens from pool.
    /// @param _pid The id of the pool. See `poolInfo`.
    /// @param _amount Amount of LP tokens to withdraw.
    function withdraw(uint256 _pid, uint256 _amount) external nonReentrant {
        PoolInfo memory pool = updatePool(_pid);
        UserInfo storage user = userInfo[_pid][msg.sender];

        require(user.amount >= _amount, "withdraw: Insufficient");

        uint256 multiplier = getBoostMultiplier(msg.sender, _pid);

        settlePendingCake(msg.sender, _pid, multiplier);

        if (_amount > 0) {
            user.amount = user.amount.sub(_amount);
            lpToken[_pid].safeTransfer(msg.sender, _amount);
        }

        user.rewardDebt = user.amount.mul(multiplier).div(BOOST_PRECISION).mul(pool.accCakePerShare).div(
            ACC_CAKE_PRECISION
        );
        poolInfo[_pid].totalBoostedShare = poolInfo[_pid].totalBoostedShare.sub(
            _amount.mul(multiplier).div(BOOST_PRECISION)
        );

        emit Withdraw(msg.sender, _pid, _amount);
    }

    /// @notice Withdraw without caring about the rewards. EMERGENCY ONLY.
    /// @param _pid The id of the pool. See `poolInfo`.
    function emergencyWithdraw(uint256 _pid) external nonReentrant {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][msg.sender];

        uint256 amount = user.amount;
        user.amount = 0;
        user.rewardDebt = 0;
        uint256 boostedAmount = amount.mul(getBoostMultiplier(msg.sender, _pid)).div(BOOST_PRECISION);
        pool.totalBoostedShare = pool.totalBoostedShare > boostedAmount ? pool.totalBoostedShare.sub(boostedAmount) : 0;

        // Note: transfer can fail or succeed if `amount` is zero.
        lpToken[_pid].safeTransfer(msg.sender, amount);
        emit EmergencyWithdraw(msg.sender, _pid, amount);
    }

    /// @notice Send DACKIE pending for burn to `burnAdmin`.
    /// @param _withUpdate Whether call "massUpdatePools" operation.
    function burnCake(bool _withUpdate) public onlyOwner {
        if (_withUpdate) {
            massUpdatePools();
        }

        uint256 multiplier = block.number.sub(lastBurnedBlock);
        uint256 pendingCakeToBurn = multiplier.mul(cakePerBlockToBurn());

        // SafeTransfer DACKIE
        _safeTransfer(burnAdmin, pendingCakeToBurn);
        lastBurnedBlock = block.number;
    }

    /// @notice Update the % of DACKIE distributions for burn, regular pools and special pools.
    /// @param _burnRate The % of DACKIE to burn each block.
    /// @param _regularFarmRate The % of DACKIE to regular pools each block.
    /// @param _specialFarmRate The % of DACKIE to special pools each block.
    /// @param _withUpdate Whether call "massUpdatePools" operation.
    function updateCakeRate(
        uint256 _burnRate,
        uint256 _regularFarmRate,
        uint256 _specialFarmRate,
        uint256 _reserveRate,
        bool _withUpdate
    ) external onlyOwner {
        require(
            _regularFarmRate > 0 && _specialFarmRate > 0,
            "MasterChefV2: Dackie rate must be greater than 0"
        );
        require(
            _burnRate.add(_regularFarmRate).add(_specialFarmRate).add(_reserveRate) == CAKE_RATE_TOTAL_PRECISION,
            "MasterChefV2: Total rate must be 1e12"
        );
        if (_withUpdate) {
            massUpdatePools();
        }
        // burn dackie base on old burn dackie rate
        burnCake(false);

        cakeRateToBurn = _burnRate;
        cakeRateToRegularFarm = _regularFarmRate;
        cakeRateToSpecialFarm = _specialFarmRate;
        cakeRateReserve = _reserveRate;

        emit UpdateDackieRate(_burnRate, _regularFarmRate, _specialFarmRate, _reserveRate);
    }

    /// @notice Update burn admin address.
    /// @param _newAdmin The new burn admin address.
    function updateBurnAdmin(address _newAdmin) external onlyOwner {
        require(_newAdmin != address(0), "MasterChefV2: Burn admin address must be valid");
        require(_newAdmin != burnAdmin, "MasterChefV2: Burn admin address is the same with current address");
        address _oldAdmin = burnAdmin;
        burnAdmin = _newAdmin;
        emit UpdateBurnAdmin(_oldAdmin, _newAdmin);
    }

    /// @notice Update whitelisted addresses for special pools.
    /// @param _user The address to be updated.
    /// @param _isValid The flag for valid or invalid.
    function updateWhiteList(address _user, bool _isValid) external onlyOwner {
        require(_user != address(0), "MasterChefV2: The white list address must be valid");

        whiteList[_user] = _isValid;
        emit UpdateWhiteList(_user, _isValid);
    }

    /// @notice Update boost contract address and max boost factor.
    /// @param _newBoostContract The new address for handling all the share boosts.
    function updateBoostContract(address _newBoostContract) external onlyOwner {
        require(
            _newBoostContract != address(0) && _newBoostContract != boostContract,
            "MasterChefV2: New boost contract address must be valid"
        );

        boostContract = _newBoostContract;
        emit UpdateBoostContract(_newBoostContract);
    }

    /// @notice Update user boost factor.
    /// @param _user The user address for boost factor updates.
    /// @param _pid The pool id for the boost factor updates.
    /// @param _newMultiplier New boost multiplier.
    function updateBoostMultiplier(
        address _user,
        uint256 _pid,
        uint256 _newMultiplier
    ) external onlyBoostContract nonReentrant {
        require(_user != address(0), "MasterChefV2: The user address must be valid");
        require(poolInfo[_pid].isRegular, "MasterChefV2: Only regular farm could be boosted");
        require(
            _newMultiplier >= BOOST_PRECISION && _newMultiplier <= MAX_BOOST_PRECISION,
            "MasterChefV2: Invalid new boost multiplier"
        );

        PoolInfo memory pool = updatePool(_pid);
        UserInfo storage user = userInfo[_pid][_user];

        uint256 prevMultiplier = getBoostMultiplier(_user, _pid);
        settlePendingCake(_user, _pid, prevMultiplier);

        user.rewardDebt = user.amount.mul(_newMultiplier).div(BOOST_PRECISION).mul(pool.accCakePerShare).div(
            ACC_CAKE_PRECISION
        );
        pool.totalBoostedShare = pool.totalBoostedShare.sub(user.amount.mul(prevMultiplier).div(BOOST_PRECISION)).add(
            user.amount.mul(_newMultiplier).div(BOOST_PRECISION)
        );
        poolInfo[_pid] = pool;
        userInfo[_pid][_user].boostMultiplier = _newMultiplier;

        emit UpdateBoostMultiplier(_user, _pid, prevMultiplier, _newMultiplier);
    }

    /// @notice Get user boost multiplier for specific pool id.
    /// @param _user The user address.
    /// @param _pid The pool id.
    function getBoostMultiplier(address _user, uint256 _pid) public view returns (uint256) {
        uint256 multiplier = userInfo[_pid][_user].boostMultiplier;
        return multiplier > BOOST_PRECISION ? multiplier : BOOST_PRECISION;
    }

    /// @notice Settles, distribute the pending DACKIE rewards for given user.
    /// @param _user The user address for settling rewards.
    /// @param _pid The pool id.
    /// @param _boostMultiplier The user boost multiplier in specific pool id.
    function settlePendingCake(
        address _user,
        uint256 _pid,
        uint256 _boostMultiplier
    ) internal {
        UserInfo memory user = userInfo[_pid][_user];

        uint256 boostedAmount = user.amount.mul(_boostMultiplier).div(BOOST_PRECISION);
        uint256 accDackie = boostedAmount.mul(poolInfo[_pid].accCakePerShare).div(ACC_CAKE_PRECISION);
        uint256 pending = accDackie.sub(user.rewardDebt);
        // SafeTransfer DACKIE
        _safeTransfer(_user, pending);
    }

    /// @notice Safe Transfer DACKIE.
    /// @param _to The DACKIE receiver address.
    /// @param _amount transfer DACKIE amounts.
    function _safeTransfer(address _to, uint256 _amount) internal {
        if (_amount > 0) {
            uint256 balance = DACKIE.balanceOf(address(this));
            if (balance < _amount) {
                _amount = balance;
            }
            DACKIE.safeTransfer(_to, _amount);
        }
    }

    function setCakePerBlock(uint256 _cakePerBlock) external onlyOwner {
        MASTERCHEF_CAKE_PER_BLOCK = _cakePerBlock;
        emit NewDackiePerBlock(_cakePerBlock);
    }

    /// @notice Withdraw unexpected tokens sent to the receiver, can also withdraw cake.
    /// @dev Callable by owner.
    /// @param _token Token address.
    function withdraw(IERC20 _token) external onlyOwner {
        uint256 amount = _token.balanceOf(address(this));
        _token.safeTransfer(msg.sender, amount);
        emit WithdrawToken(address(_token), msg.sender, amount);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../utils/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor () internal {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

{
  "compilationTarget": {
    "contracts/MasterChefV2.sol": "MasterChefV2"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 99999
  },
  "remappings": []
}