#include <iostream>
#include <fstream>
using namespace std;
int v[2000001],i,n,sol;
int main()
{
    ifstream f("ciur.in");
    ofstream g("ciur.out");
    f>>n;
    i=1;
    while (2*i<=n)
          {
              i++;
              v[2*i]=1;
          }
    i=1;
    while (3*i<=n)
          {
              i++;
              v[3*i]=1;
          }
    for (i=2;i<=n;i++)
         {
             if (v[i]==0) sol++;
         }
    g<<sol;
    return 0;
}