#include <iostream>
#include <fstream>
using namespace std;

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

int main()
{
	int m,a,b,ct,n,i,j;
	ifstream f("fractii.in");
	ofstream g("fractii.out");
	f>>n;
	ct=0;
	for(i=1 ; i<=n ; i++)
		for(j=i+1 ; j<=n ; j++)
		{a=i ; b=j;
		m=cmmdc(a,b);
		if (m==1) ct+=1;
		}
	ct=2*ct+1;

	g<<ct<<"\n";
	f.close();
	g.close();
	return 0;
}