contract ERC20Standard {


    // total amount of tokens
    function totalSupply() public constant returns (uint256) ;

    /*
     *  Events
     */
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    /*
     *  Public functions
     */
    function transfer(address _to, uint256 _value) public returns (bool);

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


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

    function balanceOf(address _owner) public constant returns (uint256);

    function allowance(address _owner, address _spender) public constant returns (uint256);
}
function totalSupply() public constant returns (uint256) ;
// total amount of tokens