#include <fstream>
#include <vector>
#include <set>
using namespace std;
int N, numar_fractii;

int IsValid (int x, int y)
{
	if (!y) return x;
	return IsValid (y, x%y);
}

void GenereazaFractii (int index)
{
	if (index > N)
	{
		return;
	}
	else
	{
		int Q = 1;
		numar_fractii++;
		while (Q < N)
		{
			Q++;
			int gcd = IsValid(index, Q);
			if (gcd == 1)
				numar_fractii++;
		}
		GenereazaFractii (index + 1);
	}
}

int main ()
{
	ifstream in ("fractii.in");
	in >> N;
	in.close();
	
	GenereazaFractii(1);
	
	ofstream out ("fractii.out");
	out << numar_fractii;
	out.close();
	
	return 0;
}