#include<iostream>
#include<fstream>
#include<stdlib.h>
#include<stdio.h>

using namespace std;

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

int main(){
	fstream in("fractii.in",ios::in);
	fstream out("fractii.out",ios::out);

	long n,numar;
	in>>n;
	numar = 2*n -1;
	for(int i = 2 ; i <= n ;i++){
		for(int j = i+1 ; j<= n; j++){
		
			if( ireductibil(i,j) == 1){
				numar = numar + 2;
			}
		}
	}
	
	out<<numar;
	return 0;
}