#include<iostream.h>
#include<fstream.h>
#define IN ifstream f("fractii.in");
#define INC f.close();
#define OUT ofstream g("fractii.out");
#define OUTC g.close();
int cmmdc(int a,int b){
	if(b==0)return a;
	else return cmmdc(b,a%b);}
int rezolva(int n){
	int nr=-1;
	for(int i=1;i<=n;i++)
	for(int j=1;j<=i;j++)
	if(cmmdc(i,j)==1)nr+=2;
	return nr;}
int citeste(){
	int n;IN f>>n;INC
	return n;}
int main(){
	OUT g<<rezolva(citeste());OUTC
return 0;}