func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long t;     cin >> t;     while (t--) {       long long n, s;       cin >> n >> s;       long long cnt = 0, x = n;       while (x) {         cnt += x % 10;         x /= 10;       }       long long ans = 0, now = 1;       while (1) {         if (cnt <= s) {           cout << ans << endl;           break;         }         long long p = n % 10;         if (!p) p = 10;         ans += (10 - p) * now;         n += 10 - p;         n /= 10;         x = n;         cnt = 0;         while (x) {           cnt += x % 10;           x /= 10;         }         now *= 10;       }     }     return 0;   }   