#include <fstream>

using namespace std;

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

int n;

long long c[1000005];

int main() {

	fin >> n;

	for (int i = 2; i <= n; i++)
		c[i] = 1LL * i * (n - 1) / n;

	for (int i = 2; i <= n; i++) {

		for (int j = i + i; j <= n; j += i)
			c[j] -= c[i];

	}

	long long sol = 0;

	for (int i = 2; i <= n; i++)
		sol += c[i];

	fout << (2 * sol) + 1 << "\n";

	return 0;
}