#include <iostream>
#include <fstream>
#include <math>

int pie(int m, int n){
int aux;
if (n>m){
	aux=n;
	n=m;
	m=aux;
	}
while (n){
	aux=n;
	n=m%n;
	m=aux;
	}
if(m>1)return 0;
else return 1;
}

int main(void){
fstream f("fractii.in", ios::in);
fstream g("fractii.out", ios::out);
int n,i,j,ct;
f>>n;
ct=1;
for (i=1;i<=n;i++)
	for(j=i+1;j<=n;j++)
   	if (pie(j,i)==1) ct=ct+2;
g<<ct;
}