func_code_string: #include <bits/stdc++.h>   using namespace std;   bool isprime(long long int n) {     if (n <= 1) return false;     if (n <= 3) return true;     if (n % 2 == 0 || n % 3 == 0) return false;     for (long long int i = 5; i * i <= n; i = i + 6)       if (n % i == 0 || n % (i + 2) == 0) return false;     return true;   }   int main() {     int t;     cin >> t;     string y =  YES n , z =  NO n ;     while (t--) {       long long int a, b, i, j;       cin >> a >> b;       if (a - b != 1)         cout << z;       else {         if (isprime(a + b))           cout << y;         else           cout << z;       }     }   }   