#include <iostream>
#include <fstream>

using namespace std;

int n, contuar = 2;
fstream ciurin, ciurout;

int main()
{
    ciurin.open("ciur.in", ios::in);

    ciurin >> n;

    ciurin.close();

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

    ciurout.open("ciur.out", ios::out);

    ciurout << contuar;

    ciurout.close();
}