contract BasicToken is ERC20Basic {
    using SafeMath for uint256;

    mapping(address => uint256) balances;

    uint256 totalSupply_;

    /**
     * @dev total number of tokens in existence
     */
    function totalSupply() public view returns (uint256) {
        return totalSupply_;
    }

    /**
     * @dev transfer token for a specified address
     * @param _to The address to transfer to.
     * @param _value The amount to be transferred.
     */
    function transfer(address _to, uint256 _value) public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[msg.sender]);

        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        emit Transfer(msg.sender, _to, _value);
        return true;
    }

    /**
     * @dev transfer token for a specified address
     * @param _to The address to transfer to.
     * @param _value The amount to be transferred.
     */
    function transferFrom(
        address _from,
        address _to,
        uint256 _value
    ) public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[_from]);

        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        emit Transfer(_from, _to, _value);
        return true;
    }

    /**
     * @dev Gets the balance of the specified address.
     * @param _owner The address to query the the balance of.
     * @return An uint256 representing the amount owned by the passed address.
     */
    function balanceOf(address _owner) public view returns (uint256) {
        return balances[_owner];
    }
}
/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
function transferFrom(
    address _from,
    address _to,
    uint256 _value
) public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[_from]);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(_from, _to, _value);
    return true;
}

/**
 * @dev transfer token for a specified address
 * @param _to The address to transfer to.
 * @param _value The amount to be transferred.
 */