#include <iostream> #include <cmath> using namespace std; bool is_prime(int n) { if (n <= 1) return false; for (int i = 2; i <= sqrt(n); i++) { if (n % i == 0) return false; } return true; } int main() { int n; cin >> n; if (is_prime(n)) { cout << n << " is a prime number" << endl; } else { cout << n << " is not a prime number" << endl; } return 0; }