contract EIP20 is EIP20Interface {



    uint256 constant private MAX_UINT256 = 2**256 - 1;

    mapping (address => uint256) public balances;

    mapping (address => mapping (address => uint256)) public allowed;


    string public name;                   //fancy name: eg Simon Bucks

    uint8 public decimals;                //How many decimals to show.

    string public symbol;                 //An identifier: eg SBX



    function EIP20(

        uint256 _initialAmount,

        string _tokenName,

        uint8 _decimalUnits,

        string _tokenSymbol

    ) public {

        balances[msg.sender] = _initialAmount;               // Give the creator all initial tokens

        totalSupply = _initialAmount;                        // Update total supply

        name = _tokenName;                                   // Set the name for display purposes

        decimals = _decimalUnits;                            // Amount of decimals for display purposes

        symbol = _tokenSymbol;                               // Set the symbol for display purposes

    }



    function transfer(address _to, uint256 _value) public returns (bool success) {

        require(balances[msg.sender] >= _value);

        balances[msg.sender] -= _value;

        balances[_to] += _value;

        Transfer(msg.sender, _to, _value); 
        //solhint-disable-line indent, no-unused-vars

        return true;

    }



    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {

        uint256 allowance = allowed[_from][msg.sender];

        require(balances[_from] >= _value && allowance >= _value);

        balances[_to] += _value;

        balances[_from] -= _value;

        if (allowance < MAX_UINT256) {

            allowed[_from][msg.sender] -= _value;

        }

         Transfer(_from, _to, _value);
         //solhint-disable-line indent, no-unused-vars

        return true;

    }



    function balanceOf(address _owner) public view returns (uint256 balance) {

        return balances[_owner];

    }



    function approve(address _spender, uint256 _value) public returns (bool success) {

        allowed[msg.sender][_spender] = _value;

         Approval(msg.sender, _spender, _value); 
        
        //solhint-disable-line indent, no-unused-vars

        return true;

    }



    function allowance(address _owner, address _spender) public view returns (uint256 remaining) {

        return allowed[_owner][_spender];

    }

}
/*
 
 Implements EIP20 token standard: https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
 
 .*/
function EIP20(

    uint256 _initialAmount,

    string _tokenName,

    uint8 _decimalUnits,

    string _tokenSymbol

) public {

    balances[msg.sender] = _initialAmount;               // Give the creator all initial tokens

    totalSupply = _initialAmount;                        // Update total supply

    name = _tokenName;                                   // Set the name for display purposes

    decimals = _decimalUnits;                            // Amount of decimals for display purposes

    symbol = _tokenSymbol;                               // Set the symbol for display purposes

}

//An identifier: eg SBX