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

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

int euclid(int a, int b){
	int i,d,r;
	if(a>b){
		d=a;
		i=b;}
	else{
		d=b;
		i=a;}
	r=d%i;
	while(r!=0){
		r=d%i;
		d=i;
		i=r;}
	return d;}

int main(){
	int n,i,j,nr=1;
	f>>n;
	for(i=1;i<n;i++)
		for(j=i+1;j<=n;j++)
			if(i==1)
				nr=nr+2;
			else if(euclid(i,j)==1)
				nr=nr+2;
	g<<nr;
	return 0;
}