#include <iostream>
#include <fstream>
using namespace std;

int main(){
    //ifstream fin("date.in");
    ifstream fin("ciur.in");
    ofstream fout("ciur.out");

    int n, cnt = 2;
    fin >> n;

    if(n == 2)
        --cnt;

    for(int i = 5; i <= n; i += 2){
        if(i % 2 != 0 && i % 3 != 0){
            ++cnt;
        }
    }
    fout << cnt;

    return 0;
}