#include <fstream>
using namespace std;

ifstream f("ciur.in");
ofstream g("ciur.out");

int x[2000000];
int n;
int main()
{
    for (int i=4;i<=2000000;i+=2)
        x[i]=1;
    for (int i=6;i<=2000000; i+=3)
        x[i]=1;
    for (int i =10; i<=2000000; i+=5)
        x[i]=1;
    for (int i=14;i<=2000000;i+=7)
        x[i]=1;
    f >> n;
    int k=0;
    for (int i= 2; i<=n;i++)
        if (x[i]==0) k++;
    g << k;
}