#include <iostream>
using namespace std;
int main()
{
    int n;
    int p = 0;
    
    cin >> n;
    
    for(int x=n; x>=1; x--)
    {
            int c = 0;
            for(int y=1; y<=x; y++)
            {
                    if(x%y==0)
                    c++;
            }
            
            if(c==2)
            {
                    cout << x << endl;
                    p++;
            }
    }
    
    cout<< p << endl;
    

return 0;
}