#include <fstream>
long cmmdc(long a, long b)
{
	long c;
	while (b)
	{
		c=a%b;
		a=b;
		b=c;
	}
	return a;
}
int main ()
{
	using namespace std;
	ifstream f("fractii.in");
	int nr=1;
	long i,j,n;
	f>>n;
	f.close();
	for (i=1; i<n; i++)
		for (j=i+1; j<=n; j++)
			if (cmmdc(i,j)==1) nr+=2;
	ofstream g("fractii.out");
	g<<nr;
	g.close();
	return 0;
}