#include <fstream>

using namespace std;

bool euclid (int a, int b)
{
	int t;

	while (a % b != 0)
	{
		a = a % b;
		t = a;
		a = b;
		b = t;
	}

	if (b == 1) return true;
	return false;
}

int nrfractiiunice(int n, int m)
{
	int nr = 0;

	for (int i = n; i < m; i++)
	{
		if(euclid(m,i))
			nr++;
	}

	return nr;
}

int main()
{
	ifstream IN("fractii.in");
	ofstream OUT("fractii.out");

	int n;
	
	IN >> n;

	int num = 2 * (n - 1) + 1;

	for (int i = 2; i <= n; i++)
		num += 2 * nrfractiiunice (i, n);

	OUT << num;
}