a.sol

//SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.8.7;

contract HealthCare {
    uint public sum_ratings = 0;
    uint public count_ratings = 0;

    function addRating(uint _rating) external {
        sum_ratings = sum_ratings+_rating;
        count_ratings+=1;
    }   
   

    // function getaverageRating() external{
    //     return sum_ratings/count_ratings;
    // }

    // function changeCity(string memory _word) external {
    //     myCity = _word;
    // }
}