#include <iostream> #include <math.h> using namespace std; bool premier(int n) { if (n % 2 == 0) return true; for (int d = 3; floor(sqrt(n)+1); d=d+2) if (n % d == 0) return false; return true; } int main() { if (premier(21)) cout << "Prim" << endl; else cout << "Pas Prim" << endl; return 0; }