#include <stdio.h>
void main()
{
  int n,i,s,j;

  printf("give me a number --> "); scanf("%d",&n);
  s=0;
  for (i=2; i<=n/2; i++) {
    if (n%i == 0) { s=1; break; }
  }
  if (s == 0) printf("%d is a prime \n",n);
  else printf("%d is not a prime\n",n);
}