func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, m, i1;   long long cont = 0;   int main() {     cin >> n;     for (long long i = 0; i < n; ++i) {       long long x, y;       cin >> x >> y;       if (x - y != 1) {         cout <<  NO  << endl;       } else {         long long p = x + y, s = 0;         for (long long j = 2; j <= sqrt(p); ++j) {           if (p % j == 0) {             s = 1;             break;           }         }         if (s == 0) {           cout <<  YES  << endl;         } else {           cout <<  NO  << endl;         }       }     }     return 0;   }   