#include <stdio.h>
#include <math.h>
int zhihsu(int i);
int main() {
    int count = 0;
    for(int i = 100;i<1000;i++)
    {
        if(zhihsu(i))
        count ++;
    }
    printf("%d",count);
    return 0;
}
int zhihsu(int i)
{
    int k = 0;
     for(int j = 2;j<=sqrt(i);j++)
     {
         if(i%j==0)
         {
             k = 0;
             break;
         }
         else
         k = 1;
     }
     return k;

}