func_code_string: #include <bits/stdc++.h>   int tcase, m;   long long n;   int gao(long long x) {     int ret = 0;     for (; x; x /= 10) ret += x % 10;     return ret;   }   int main() {     scanf( %d , &tcase);     while (tcase--) {       scanf( %lld%d , &n, &m);       if (gao(n) <= m) {         printf( 0 n );         continue;       }       long long x = 10;       while (gao(n + (x - n % x)) > m) x *= 10;       printf( %lld n , x - n % x);     }     return 0;   }   