#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
bool fr[2000005];
int main()
{
    int n,c=0,ok,x;
    cin>>n;
    c=n-n/2;
    c=c-n/6;
    c=c-n/30;
    c=c-n/210;
    x=210;
    for (int i=10;i<=sqrt(n);i++)
    {
        ok=0;
        for (int j=2;j<=sqrt(i);j++)
            if (i%j==0)
            {
                ok=1;
                break;
            }
        if (ok==0)
        {
            x=x*i;
            c=c-n/x;
        }
    }
    cout<<c;
    return 0;
}