pragma solidity ^0.4.19;

interface IERC20 {
    function totalSupply () constant returns (uint256 totalSuppy);
    function balanceOf(address _owner) constant returns (uint256 balance);
    function transfer(address _to, uint256 _value) returns (bool success);
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success);
    function approve(address _spender, uint256 _value) returns (bool success);
    function allowance(address _owner, address _spender) constant returns (uint256 remaining);
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
contract POS is IERC20 {
    uint public constant _totalSupply = 200000000;
    string public constant symbol = "Turd";
    string public constant name = "POS";
    uint8 public constant decimals = 0;
    
    mapping (address => uint256) balances;
    mapping(address => mapping(address => uint256)) allowed;
    function POS() public{
        balances[msg.sender] = _totalSupply;
    }
    
    function totalSupply() constant returns (uint256 totalSupply) {
        return _totalSupply;
    }
    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }
    function transfer(address _to, uint256 _value) returns (bool success) {
        require(
            balances[msg.sender] >= _value
            && _value > 0
            );
            balances[msg.sender] -= _value;
            balances[_to] += _value;
            Transfer(msg.sender, _to, _value);
            return true;
    }
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        require(
            allowed[_from][msg.sender] >= _value
            && balances[_from] >= _value
            && _value > 0
            );
            balances[_from] -= _value;
            balances[_to] += _value;
            allowed[_from][msg.sender] -= _value;
            Transfer(_from, _to, _value);
            return true;
    }
    function approve(address _spender, uint256 _value) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }
    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }
    
}