#include <stdio.h>
int main() {
	int n, count = 0;
	printf("Nhap n: ");
	scanf_s("%d", &n);
	for (int i = 1; i <= n; i++) {
		if (n % i == 0) count++;
	}
	if (count == 2) printf("%d la so nguyen to", n);
	else printf("%d khong la so nguyen to", n);
}