/* Note:Your choice is C IDE */
#include "stdio.h"
#include "math.h"
void main()
{
    int m,i,k;
    scanf("%d",&m);
    k=sqrt(m);
    for(i=2;i<=k;i++);
       if(m%i==0)break;
    if(i>k)printf("%d is a prime number\n",m);
    else printf("%d is not a prime number\n",m);
}