#include<stdio.h>
int main()
{
int i, n;
printf("please enter a number:");
scanf_s("%d", &n);
while (n <=1)
{
printf("enter a number again:");
scanf_s("%d", &n);
}
for(i=2;i<=n-1;i++)
{
if (n % i == 0)
printf("no");
else
printf("yes");
break;
}
return 0;
}