#include <fstream>

int cmmdc(int a, int b)
{
	while(b != 0)
	{
		r = a%b;
		a = b;
		b = r;
	}
	return r;
}

typedef unsigned int natural;
typedef double real;
typedef int intreg;

using namespace std;

/***************/

ifstream fin("fractii.in");
ofstream fout("fractii.out");

natural numar;

/***************/

natural rezolva()
{
	natural ans = 0;
	numar = numar+1;
	for(unsigned int i = 1; i < numar; i++)
	{
		for(unsigned int j = 1; j < numar; j++)
		{
			if(cmmdc(i, j) == 1)
			{
				ans++;
			}
		}
	}
	return ans;
}


#include <iostream>
int main(int argc, char *argv[], char* env[])
{
	fin >> numar;
	fout << rezolva();

	return 0;
}