#include <fstream>
#include <iostream>
using namespace std;
int ired(long p, long q)
{long a, b; 
a=p; b=q;
while(a!=b){
	if(a>b)a=a-b;
	else b=b-a;}
return a;}
int main ()
{int nr;
long n, i, j;
ifstream f("fractii.in");
ofstream g("fractii.out");
f>>n;
nr=0;i=1;j=1;
while(j<=n && i<=n){
		if(ired(i, j)==1) nr++;
		j++;
		if(j>n) {j=1; i++;}}
		g<<nr;
		f.close ();
		g.close ();
		return 0;}