contract GrandTurismoRacing {
    // Public variables of the token
    using SafeMath for uint;
    string public name;
    string public symbol;
    uint8 public decimals = 18;
    uint256 public totalSupply;

    // This creates an array with all balances
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    // This generates a public event on the blockchain that will notify clients
    event Transfer(address indexed from, address indexed to, uint256 value);

    // This generates a public event on the blockchain that will notify clients
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);


    /**
     * Constructor function
     *
     * Initializes contract with initial supply tokens to the creator of the contract
     */
    uint256 initialSupply = 120000;
    string tokenName = 'Grand Turismo Racing';
    string tokenSymbol = 'GTR';
    constructor() public {
        totalSupply = initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
        balanceOf[msg.sender] = totalSupply;                // Give the creator all initial tokens
        name = tokenName;                                // Set the name for display purposes
        symbol = tokenSymbol;                               // Set the symbol for display purposes
    }

    /**
     * Internal transfer, only can be called by this contract
     */
    function _transfer(address _from, address _to, uint _value) internal {
        require(_to != address(0));
        require(balanceOf[_from] >= _value);
        require(balanceOf[_to].add(_value) >= balanceOf[_to]);
        uint previousBalances = balanceOf[_from].add(balanceOf[_to]);
        balanceOf[_from]=balanceOf[_from].sub(_value);
        balanceOf[_to]=balanceOf[_to].add(_value);
        emit Transfer(_from, _to, _value);
        require(balanceOf[_from].add(balanceOf[_to]) == previousBalances);
    }

    function transfer(address _to, uint256 _value) external returns (bool success) {
        _transfer(msg.sender, _to, _value);
        return true;
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(_value <= allowance[_from][msg.sender]);     // Check allowance
        allowance[_from][msg.sender].sub(_value);
        _transfer(_from, _to, _value);
        return true;
    }

    function approve(address _spender, uint256 _value) public
        returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }
}
function _transfer(address _from, address _to, uint _value) internal {
        require(_to != address(0));
        require(balanceOf[_from] >= _value);
        require(balanceOf[_to].add(_value) >= balanceOf[_to]);
        uint previousBalances = balanceOf[_from].add(balanceOf[_to]);
        balanceOf[_from]=balanceOf[_from].sub(_value);
        balanceOf[_to]=balanceOf[_to].add(_value);
        emit Transfer(_from, _to, _value);
        require(balanceOf[_from].add(balanceOf[_to]) == previousBalances);
    }
/**
 * Internal transfer, only can be called by this contract
 */