#include <fstream>

using namespace std;

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

int fractii = 0;
void fa_fractii(int n) {
	int num, denum;
	fractii = n;
	for (num = 2; num <= n; num++) {
		for (denum = 1; denum <= n; denum++) {
			if ((num % denum != 0 && denum % num != 0) || denum == 1)
				fractii++;
		}
	}
}

int main()
{
	int n;
	in >> n;
	fa_fractii(n);
	out << fractii;
}