func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int t;     cin >> t;     while (t--) {       string n;       int s;       cin >> n >> s;       reverse(n.begin(), n.end());       char temp[] =  0 ;       n.insert(n.size(), temp);       int sum = 0;       for (int i = 0; i < n.size(); i++) sum += n[i] - 48;       char ans[25];       for (int i = 0; i < 25; i++) ans[i] = 0;       ans[0] =  0 ;       int i = 0;       while (sum > s) {         int dig = (n[i] - 48);         int car = 0;         sum -= dig;         n[i] =  0 ;         if (dig > 0) {           ans[i] = 10 - dig + 48;           car = 1;         } else           ans[i] =  0 ;         for (int j = i + 1; car; j++) {           int t = (n[j] - 48 + car);           if (t == 10)             sum -= n[j] - 48;           else             sum++;           n[j] = (t % 10) + 48;           car = t / 10;         }         i++;       }       int size = 0;       while (ans[++size])         ;       reverse(ans, ans + size);       cout << ans <<   n ;     }   }   