// ConsoleApplication1.cpp : Defines the entry point for the console application.
//


#include<iostream>
#include <fstream>

using namespace std;

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

int n;
int cmmdc(int a,int b)
{
	int r=a%b;
	while(r)
	{
		a=b;
		b=r;
		r=a%b;
	}
	return b;
}
int numara_fractii(int p)
{
	int nr_p=0;
	for(int q=2;q<=n;q++)
		if(cmmdc(p,q)==1)
			nr_p++;
	return nr_p;
}
int main()
{
	f>>n;
	int p,nr=2*n-1;
	for(int i=2;i<=n;i++)
	{
		p=i;
		nr=nr+numara_fractii(p);
	}
	g<<nr;
	return 0;
}