func_code_string: #include <bits/stdc++.h>   using namespace std;   bool pr(int x) {     bool p = 0;     if (x % 2 == 0)       p = (x == 2);     else {       long long d = 3;       while (d * d <= x && x % d != 0) {         d += 2;       }       if (d * d > x) p = (x != 1);     }     return p;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     bool fl;     int n, m;     cin >> n >> m;     fl = pr(m);     for (int i = n + 1; i < m; ++i) {       if (pr(i)) {         fl = 0;       }     }     if (fl) {       cout <<  YES ;     } else {       cout <<  NO ;     }     return 0;   }   