#include <stdio.h>

long lnko(long a, long b)
{
	while (a > 1 && b > 1)
	{
		if (a > b)
			a = a%b;
		else b = b%a;
	}
	return (a < b) ? (a) : (b);
}

int main()
{
	FILE *input = fopen("fractii.in", "r");
	FILE *output = fopen("fractii.out", "w");

	long n;
	long counter;

	fscanf(input, "%ld", &n);

	counter = 0;
	for (long i = 1; i <= n; i++)
	{
		for (long j = i + 1; j <= n; j++)
		{
			if (lnko(i, j) == 1)
				counter++;
		}
	}

	fprintf(output, "%ld", counter * 2 + 1);

	return 0;
}