#include <iostream>
#include <fstream>
#include <algorithm>
#include <stdio.h>
#include <string>
#include <math.h>
#include <vector>
#define lm 1000001
#define pb push_back

using namespace std;

int n;
bool l[lm];

int Euclid (int a,int b)
{
    if(!b)
        return a;
    return Euclid (b,a%b);
}
int main()
{
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    f>>n;
    for (int i=2; i<=n; i++)
        if(!l[i])
        {
            for (int j=i+i; j<=n; j+=i)
            {
                l[j]=true;
            }
        }
    int res=n;
    for (int i=2; i<=n; i++)
    {
        for (int j=2; j<=n; j++)
            {
                if(i!=j)
                {
                    if(!l[j] && !l[i])
                        res++;
                    else
                        if(Euclid(i,j)==1)
                            res++;
                }
            }
        res++;
    }
    g<<res;

 return 0;
}