func_code_string: #include <bits/stdc++.h>   using namespace std;   bool isPrime(int num);   int main() {     int n;     cin >> n;     for (int i = 1; i <= 1000; i++) {       if (!(isPrime(n * i + 1))) {         cout << i;         break;       }     }     return 0;   }   bool isPrime(int num) {     if (num <= 1)       return false;     else if (num == 2)       return true;     else if (num % 2 == 0)       return false;     else {       bool prime = true;       int divisor = 3;       double num_d = static_cast<double>(num);       int upperLimit = static_cast<int>(sqrt(num_d) + 1);       while (divisor <= upperLimit) {         if (num % divisor == 0) prime = false;         divisor += 2;       }       return prime;     }   }   