#include <fstream>

using namespace std;

long cmmdc(long a, long b) {
	while (a!=b) 
		if (a>b) a=a-b;
		else b=b-a;
	return a;
}

long div (long x) {
	long n=0;
	for (long i=1 ; i<x ; i++)
		if (cmmdc(x,i)==1) n++;
	return n;
}

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

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