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