#include <fstream>
unsigned int N,x,k,c,i;
using namespace std;
int main() {
    ifstream fin("ciur.in");
    ofstream fout("ciur.out");
    fin>>N;
    k=0;
    for(x=2;x<=N;x++)
    {
        c=x;
        for(i=1;i<=c/2;i++)
        {
            if(c%i==0&&i!=1)
                i=c/2;
            else
                if(i==c/2)
                    k++;
        }
    }
    fout<<k;
    return 0;
}