/* Bai tap 1_16 - Tinh xem so N co phai la so nguyen to khong? */

#include <stdio.h>

#include <math.h>

void main()

{

  int N, i, OK = 1;

  printf("

Nhap gia tri N : ");

  scanf("%d", &N);

  for (i=2; i<(int)sqrt(N); i++)

    if (N%i == 0)

    {

      OK = 0;

      break;

    }

  if (OK)

   printf("

So %d la so nguyen to.", N);

  else

   printf("

So %d khong phai la so nguyen to.", N);

  getch();

}