#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int cmmdc(int a,int b)
{
	while (a!=b)
		if (a>b)
			a-=b;
		else
			b-=a;
	return a;
}
int main()
{
	int i,n,p,q,ct;
	f>>n;
	ct=n*2;
	p=2;
	q=3;
	while (p<=n)
	{
		while (q<=n)
		{
			if (cmmdc(p,q)==1)
				ct++;
			if (p%2==0)
				q+=2;
			else
				q++;
		}
		p++;
		q=2;
	}
	g<<ct;
}