func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxx = (int)1e7;   long long SOD(long long n) {     long long ans = 0;     while (n) {       ans += (n % 10);       n /= 10;     }     return ans;   }   int main() {     int T;     cin >> T;     while (T--) {       vector<int> num;       long long n, s, nnn;       cin >> n >> s;       nnn = n;       if (SOD(n) <= s) {         cout << 0 << endl;         continue;       }       while (n) {         num.push_back(n % 10);         n /= 10;       }       reverse(num.begin(), num.end());       int sum = 0;       int start = 0;       for (int i = 0; i < num.size(); i++) {         sum += num[i];         if (sum >= s) {           if (i != 0 && num[i - 1] != 9) {             num[i - 1]++;             start = i;             break;           }           if (i == 0) {             num.insert(num.begin(), 1);             start = 1;             break;           } else if (num[i - 1] == 9) {             while (i != 0 && num[i - 1] == 9) {               i--;             }             i--;           }         }       }       for (int i = start; i < num.size(); i++) {         num[i] = 0;       }       int p = num.size() - 1;       long long nn = 0;       for (int i = 0; i < num.size(); i++) {         nn += num[i] * round(pow(10, p));         p--;       }       cout << (nn - nnn) << endl;     }     return 0;   }   