#include <iostream>
#include <fstream>
using namespace std;

int euclid(int a, int b)
{
	int c;
	while (b) {
		c = a % b;
		a = b;
		b = c;
	}
	return a;
}

int prime(int a, int b)
{
	if (euclid(a, b) == 1)
		return 1;
	else return 0;
}

int main()
{
	ifstream fin("fractii.in");
	ofstream fout("fractii.out");
	int p, q, n, k, contor;
	fin >> n;
	contor = 1;
	for (p = n; p >= 2; --p)
	{
		k = 0;
		for (q = p-1; q >= 1; --q)
		{
			if (prime(p, q))
				k++;
		}
		contor += 2 * k;
	}
		
	fout << contor;
	return 0;
}