#include <stdio.h>

int main ()
{
	int n, i, j, k;
	freopen ("fractii.in", "r", stdin);
	freopen ("fractii.out", "w", stdout);
	scanf ("%d", &n);
	k = n;
	for (i = 2; i <= n; i++)
	{
		for (j = 1; j <= n; j++)
		{
			if (j == 1)
				k++;
			else
			{
				if (i % j != 0 && j % i != 0)
					k++;
			}
		}
	}
	printf ("%d\n", k);
	return 0;
}