#include <stdio.h>

long cmmdc (long a, long b)
{
	if (b==0) return a;
	return cmmdc (b, a%b);
}

int main()
{
	long n, i , j;
	freopen ("fractii.in", "r", stdin);
	scanf ("%ld", &n);
	fclose(stdin);
	
	long s=1;
	for (i=1; i<=n; ++i)
		for (j=i+1; j<=n; ++j)
			if (cmmdc (i,j)==1)
				s+=2;
	
	freopen ("fractii.out", "w", stdout);
	printf ("%ld", s);
	fclose(stdout);
	return 0;
}