pragma solidity 0.5.4;

interface Token {
	function totalSupply() external view returns (uint256);
	function balanceOf(address who) external view returns (uint256);
	
    function transfer(address to, 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 sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

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

        return c;
    }
}

contract DogacoinToken is Token {
	string public constant name = "DOGACOIN";
	string public constant symbol = "DOGA";
	uint8 public constant decimals = 6;
	uint256 private _totalSupply = 20000000000 * (uint(10) ** decimals);

    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

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

	constructor() public {
		_balances[msg.sender] = _totalSupply;
    }

    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 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 transfer(address to, uint256 value) public returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint256 value) public returns (bool) {
        _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);
        _transfer(from, to, value);
        emit Approval(from, msg.sender, _allowed[from][msg.sender]);
        return true;
    }

    function _transfer(address from, address to, uint256 value) internal {
        require(to != address(0));

        _balances[from] = _balances[from].sub(value);
        _balances[to] = _balances[to].add(value);
        emit Transfer(from, to, value);
    }
}

{
  "compilationTarget": {
    "DogacoinToken.sol": "DogacoinToken"
  },
  "evmVersion": "byzantium",
  "libraries": {},
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}