pragma solidity ^0.4.26;
contract HPB {
    address public owner;
    mapping (address => uint) public balances;
    address[] public users;
    uint256 public total=0;
    uint256 constant private MAX_UINT256 = 2**256 - 1;
    mapping (address => mapping (address => uint256)) public allowed;
    uint256 public totalSupply=10000000000000000;
    string public name="Health Preservation Treasure";
    uint8 public decimals=8;
    string public symbol="HPT";
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    constructor() public{
        owner = msg.sender;
        balances[msg.sender] = totalSupply;
    }

    function userCount() public view returns (uint256) {
        return users.length;
    }

    function getTotal() public view returns (uint256) {
        return total;
    }
    function balanceOf(address _owner) public view returns (uint256 balance) {
        return balances[_owner];
    }

    function contractBalance() public view returns (uint256) {
        return (address)(this).balance;
    }
    function transfer(address _to, uint256 _value) public returns (bool success) {
        require(balances[msg.sender] >= _value);
        balances[msg.sender] -= _value;
        balances[_to] += _value;
        emit Transfer(msg.sender, _to, _value);
        return true;
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        uint256 allowance = allowed[_from][msg.sender];
        require(balances[_from] >= _value && allowance >= _value);
        balances[_to] += _value;
        balances[_from] -= _value;
        if (allowance < MAX_UINT256) {
            allowed[_from][msg.sender] -= _value;
        }
        emit Transfer(_from, _to, _value);
        return true;
    }

    function approve(address _spender, uint256 _value) public returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }

    function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

    function() public payable {
        if (msg.value > 0 ) {
            total += msg.value;
            bool isfind=false;
            for(uint i=0;i<users.length;i++)
            {
                if(msg.sender==users[i])
                {
                    isfind=true;
                    break;
                }
            }
            if(!isfind){users.push(msg.sender);}
        }
    }
}