#include<fstream>
#include<math.h>

bool divComun(int a, int b)
{
	int c;
	a < b ? c = b : c = a;
	if (a%b == 0 || b%a == 0) return true;
	if (a % 2 == 0 && b % 2 == 0) return true;
	for (int i = 3; i <=c/2; i+=2)
	{
		if (a%i == 0 && b%i == 0) return true;
	}
	return false;
}

int main()
{
	std::ifstream f("fractii.in");
	std::ofstream g("fractii.out");
	int n;
	f >> n;
	f.close();
	int nr = 2 * n - 1;
	for (int i = 2; i < n; i++)
	{
		for (int j = i + 1; j <= n; i%2==0?j+=2:j++)
		{
			if (!divComun(i, j)) nr += 2;
		}
	}
	g << nr;
	g.close();
	return 0;
}