#include <iostream>

int main() {

	int n, i, j, k;
	int nr, min;
	bool okay;

	std::cin >> n;
	nr = 2 * n - 1;

	for ( i = 2; i <= n; i++ ) {
		for ( j = 2; j < i; j++ ) {
			okay = 1;
			for ( k = 2; k <= j; k++ ) {
				if ( j % k == 0 && i % k == 0 ) okay = 0;
			}
			if ( okay ) nr += 2;
		}
	}
	std::cout << nr << std::endl;

	return 0;
}