contract ERC20 {
    
    //functions
    function balanceOf(address _owner) public view returns (uint 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 view returns (uint remaining);
    function burn(uint _value) public returns (bool success);
    
    //events
    event Transfer(address indexed _from, address indexed _to, uint _value);
    event Approval(address indexed _owner, address indexed _spender, uint _value);
    event Burn(address indexed _from, uint _value);
}
function balanceOf(address _owner) public view returns (uint balance);
//functions