#include <fstream.h>

#define input ("fractii.in")
#define output ("fractii.out")

long cmmdc (long i,long j)
{
	while (i!=j)
		if (i>j)
			i = i-j;
		else
			j = j-i;
	return i;
}

int main ()
{
	ifstream fin (input);
	ofstream fout (output);

	long n,i,j,s=0;

	fin>>n;

	for (i=1;i<=n;i++)
		for (j=i+1;j<=n;j++)
		   if (cmmdc(i,j) == 1)
				s++;

	fout<<s*2+1;

	return 0;
}