#include <iostream>
#include <fstream>

using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");

int cmmdc(int a, int b)
{
    int r;
    while(b)
    {
        r = a % b;
        a = b;
        b = r;
    }
    return a;
}

int main()
{
    int n, nr = 1;
    f>>n;
    for(int i = 1;i < n;i++)
        for(int j = i + 1;j <= n;j++)
            if(cmmdc(i, j) == 1)
                nr += 2;
    g<<nr;
}