#include <fstream>

using namespace std;
int ciur(int len){
    int v[100], x = 0;
   for(int i = 2; i <= len; i++){
        v[i * 2] = -1;
        v[i * 3] = -1;
        v[i * 5] = -1;
        v[i * 7] = -1;
       if(v[i] != -1){
            x++;
       }
   }
   return x;
}
int main(){
    int x;
    ifstream fin("ciur.in");
    ofstream fout("ciur.out");
    fin >> x;
    fout << ciur(x);
    return 0;
}