#include <iostream>
#include <math.h>
#include <fstream>
using namespace std;
ifstream in("fractii.in");
ofstream out("fractii.out");
int main()
{
    int x,n,d,aux,s1=0,s;
    in>>n;
    s=n*n-n+1;
    aux=n-1;
    for (int i=2;i<=n;i++)
    {
        x=i;
        aux--;
        d=2;
        while (x!=1)
        {
            if (x%d==0)
            {
                while (x%d==0)
                    x=x/d;
                s1=s1+(aux/d)*2;
            }
            d++;
        }
    }
    out<<s-s1;
}