pragma solidity ^0.5.0;

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function balanceOf(address who) external view returns (uint256);

    function allowance(address owner, address spender)
        external
        view
        returns (uint256);

    function transfer(address to, uint256 value) external returns (bool);

    function approve(address spender, uint256 value) external returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        assert(c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a / b;
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }

    function ceil(uint256 a, uint256 m) internal pure returns (uint256) {
        uint256 c = add(a, m);
        uint256 d = sub(c, 2);
        return mul(div(d, m), m);
    }
}

contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    constructor(
        string memory name,
        string memory symbol,
        uint8 decimals
    ) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

contract BUNA is ERC20Detailed {
    using SafeMath for uint256;
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowed;

    string constant tokenName = "BidenCoin";
    string constant tokenSymbol = "Biden";
    uint8 constant tokenDecimals = 18;
    uint256 _totalSupply = 1000000000000 * 10**18;
    uint256 public basePercent = 100;
    uint256 public _burnStopAmount;
    uint256 public _lastTokenSupply;

    address payable charity = 0x3C6494d4Ea18268d621e3a72Ba0fAB5ad581248C;

    constructor()
        public
        payable
        ERC20Detailed(tokenName, tokenSymbol, tokenDecimals)
    {
        _mint(msg.sender, _totalSupply);
        _burnStopAmount = 0;
        _lastTokenSupply = 200000 * 10**18;
    }

    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address owner) public view returns (uint256) {
        return _balances[owner];
    }

    function allowance(address owner, address spender)
        public
        view
        returns (uint256)
    {
        return _allowed[owner][spender];
    }

    function findOnePercent(uint256 value) public view returns (uint256) {
        uint256 roundValue = value.ceil(basePercent);
        uint256 onePercent = roundValue.mul(basePercent).div(1000);
        onePercent = onePercent.mul(2);
        // uint256 twentyPercent = onePercent.mul(basePercent).div(1000);
        return onePercent;
    }

    function transfer(address to, uint256 value) public returns (bool) {
        require(value <= _balances[msg.sender]);
        require(to != address(0));

        /// buring 10%
        uint256 tokensToBurn = findOnePercent(value);
        uint256 tokensToTransfer = value.sub(tokensToBurn);

        // transaction fee 5%
        uint256 tokensForFee = findOnePercent(value);
        tokensToTransfer = value.sub(tokensForFee);

        // distribute 5%
        uint256 tokensForCharity = findOnePercent(value);
        tokensToTransfer = value.sub(tokensForCharity);

        _balances[msg.sender] = _balances[msg.sender].sub(value);
        _balances[to] = _balances[to].add(tokensToTransfer);

        _totalSupply = _totalSupply.sub(tokensToBurn);

        emit Transfer(msg.sender, to, tokensToTransfer);
        emit Transfer(msg.sender, address(0), tokensToBurn);
        emit Transfer(msg.sender, charity, tokensForCharity);
        return true;
    }

    function multiTransfer(address[] memory receivers, uint256[] memory amounts)
        public
    {
        for (uint256 i = 0; i < receivers.length; i++) {
            transfer(receivers[i], amounts[i]);
        }
    }

    function approve(address spender, uint256 value) public returns (bool) {
        require(spender != address(0));
        _allowed[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) public returns (bool) {
        require(value <= _balances[from]);
        require(value <= _allowed[from][msg.sender]);
        require(to != address(0));

        _balances[from] = _balances[from].sub(value);

        uint256 tokensToBurn = findOnePercent(value);
        uint256 tokensToTransfer = value.sub(tokensToBurn);

        _balances[to] = _balances[to].add(tokensToTransfer);
        _totalSupply = _totalSupply.sub(tokensToBurn);

        _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);

        emit Transfer(from, to, tokensToTransfer);
        emit Transfer(from, address(0), tokensToBurn);

        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue)
        public
        returns (bool)
    {
        require(spender != address(0));
        _allowed[msg.sender][spender] = (
            _allowed[msg.sender][spender].add(addedValue)
        );
        emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue)
        public
        returns (bool)
    {
        require(spender != address(0));
        _allowed[msg.sender][spender] = (
            _allowed[msg.sender][spender].sub(subtractedValue)
        );
        emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
        return true;
    }

    function _mint(address account, uint256 amount) internal {
        require(amount != 0);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    function burn(uint256 amount) external {
        _burn(msg.sender, amount);
    }

    function _burn(address account, uint256 amount) internal {
        require(amount != 0);
        require(amount <= _balances[account]);
        _totalSupply = _totalSupply.sub(amount);
        _balances[account] = _balances[account].sub(amount);
        emit Transfer(account, address(0), amount);
    }

    function burnFrom(address account, uint256 amount) external {
        require(amount <= _allowed[account][msg.sender]);
        _allowed[account][msg.sender] = _allowed[account][msg.sender].sub(
            amount
        );
        _burn(account, amount);
    }
}

{
  "compilationTarget": {
    "BUNA.sol": "BUNA"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}