#include <fstream>
#include <algorithm>

using namespace std;

/***************/

ifstream fin("fractii.in");
ofstream fout("fractii.out");

int numar = 0;

/***************/

#include <iostream>
int main()
{
	fin >> numar;
	int ans = 0;
	numar = numar+1;
	for(int i = 2; i < numar; i++)
	{
		for(int j = 1; j < numar; j++)
		{
			if (__gcd(i, j) == 1)
			{
				ans++;
			}
		}
	}
	fout << ans+2*numar-1;

	return 0;
}

/*
N=1
	1/1

N=2
	... 2/1 2/2


*/