contract ERC20Basic {
  // events
  event Transfer(address indexed from, address indexed to, uint256 value);

  // public functions
  function totalSupply() public view returns (uint256);
  function balanceOf(address addr) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
}
function totalSupply() public view returns (uint256);
// public functions