contract ERC20 {
    // Standard interface
    function totalSupply() public constant returns(uint256 _totalSupply);
    function balanceOf(address who) public constant returns(uint256 balance);
    function transfer(address to, uint value) public returns(bool success);
    function transferFrom(address from, address to, uint value) public returns(bool success);
    function approve(address spender, uint value) public returns(bool success);
    function allowance(address owner, address spender) public constant returns(uint remaining);
    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}
function totalSupply() public constant returns(uint256 _totalSupply);
// Standard interface