#include <iostream>
#include <math.h>

using namespace std;

bool so_nguyen_to(int n) {
	for (int i = 2; i <= n/2; i++) {
		if (n % i == 0) return false;
	}
	return true;
}

int main() {
	int n;
	bool nguyento = true;
	cout<<"Nhap n: "; cin>>n;
	for (int i = 2; i <= round(sqrt(n)); i++) {
		if (n % i == 0) {
			nguyento = false;
			cout<<n<<" khong la so nguyen to";
			break;
		}
	}
	if (nguyento) {
		cout<<n<<" la so nguyen to";
	}
	return 0;
}