#include "stdio.h"
#include "malloc.h"

using namespace std;

int main()
{
    int aux[4],n,i,ok,nr(0);

    FILE* f=fopen("ciur.in","r");
    FILE* g=fopen("ciur.out","w");

    fscanf(f,"%i",&n);

    aux[0]=2;
    aux[1]=3;
    aux[2]=5;
    aux[3]=7;

    for(i=2;i<=n;i++)
    {
        ok=0;
        for(int m=0;m<4 && ok==0;m++)
            if(i%aux[m]==0 && i!=aux[m])
                ok=1;
        if(ok==0)
            nr++;
    }

    fprintf(g,"%i",nr);

    fclose(f);
    fclose(g);

    return 0;
}