func_code_string: #include <bits/stdc++.h>   using namespace std;   long long modPower(long long num, long long r) {     if (r == 0) return 1;     if (r == 1) return num % 1000000007;     long long ans = modPower(num, r / 2) % 1000000007;     if (r % 2 == 0) {       return (ans * ans) % 1000000007;     }     return (((ans * ans) % 1000000007) * num) % 1000000007;   }   long long nCr(long long n, long long r) {     long long res = 1;     if (r > n - r) {       r = n - r;     }     for (long long i = 0; i < r; i++) {       res *= (n - i);       res /= (i + 1);     }     return res;   }   bool isPrime(long long n) {     if (n <= 1) return false;     if (n <= 3) return true;     if (n % 2 == 0 || n % 3 == 0) return false;     for (int i = 5; i * i <= n; i = i + 6)       if (n % i == 0 || n % (i + 2) == 0) return false;     return true;   }   int pos(int a) {     if (a < 0)       return (-1) * a;     else       return a;   }   unsigned long long highestPowerof2(unsigned long long n) {     unsigned long long p = (unsigned long long)log2(n);     return (unsigned long long)pow(2, p);   }   long long gcd(long long a, long long b) {     if (b == 0) return a;     return gcd(b, a % b);   }   vector<int> fprint(vector<int> A, int n) {     vector<int> fprint;     for (int i = 0; i < n - 1; i++) {       fprint.push_back(A[i] + A[i + 1]);     }     sort(fprint.begin(), fprint.end());     return fprint;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     long long grr;     cin >> grr;     while (grr--) {       long long count = 0;       long long n, s;       cin >> n >> s;       long long c = n, rev = 0;       long long x = 10;       long long sum = 0, sum2 = 0, len = 0;       while (c > 0) {         sum += c % 10;         rev = rev * 10 + c % 10;         len++;         c = c / 10;       }       if (sum <= s)         cout << 0 <<   n ;       else {         sum2 = 0;         while (sum2 + rev % 10 < s && rev > 0) {           count++;           sum2 += rev % 10;           rev /= 10;         }         long long x = len - count, y = 1;         while (x--) {           y *= 10;         }         n = n % y;         x = 10;         while (n / x != 0) {           x *= 10;         }         cout << x - n <<   n ;       }     }   }   