#include <fstream>

using namespace std;

long div (long x) {
	long n=0;
	for (long i=2 ; i<x ; i++)
		if (x%i==0 || (x%2==0 && i%2==0)) n++;
	return n;
}

void fractii() {
	ifstream f("fractii.in");
	ofstream g("fractii.out");
	long nr=0,n;
	f>>n;
	f.close();
	for (long i=1 ; i<=n ; i++) nr=nr+(i-div(i)-1);
	g<<nr*2-1;
	g.close();
}

int main() {
	fractii();
	return 0;
}