func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long int t;     cin >> t;     while (t--) {       long long int a, b, c, d;       cin >> a >> b;       if (a % b == 0)         cout << 0 << endl;       else if (b > a)         cout << (b - a) << endl;       else {         c = a / b;         c++;         c = c * b;         cout << (c - a) << endl;       }     }     return 0;   }   