class challange

pragma solidity ^0.5.1;

contract count {
    
    uint counter; 

    constructor () public {
        counter = 0;
    } 
    
    
    function increment(uint _counter) public {
        require(msg.sender != tx.origin);
        counter += _counter; 
    }
    
    function decrement() public {
        counter --;
    }
    
    function getCount() public view returns(uint){
        return counter;
    }
    
}