#include <stdio.h>

#define FILE_IN		"fractii.in"
#define FILE_OUT	"fractii.out"

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

int countFractions(int n)
{
	int count = 1;
	int i, j;
	for (i = 0; i < n; ++i)
		for (j = i + 1; j < n; ++j)
			if (1 == cmmdc(i + 1, j + 1))
				count += 2;
	return count;
}

int main(int argc, char **argv)
{
	int n;
#ifndef _HOME_
	freopen(FILE_IN, "r", stdin);
	freopen(FILE_OUT, "w", stdout);
#endif

	scanf("%d", &n);
	printf("%d\n", countFractions(n));

	return 0;
}