#include <iostream>
#include <fstream>
using namespace std;
int a,b,n,nr=0;
int main()
{
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    f>>n;
    a=1;b=1;
    while(a<=n)
    {
        while(b<=n)
        {
            if ((b==1)or(a%b!=0)) {nr++;}
            b++;
        }
        a++;
        b=1;
    }
    g<<nr-1;
    return 0;
}