#include<iostream>;
#include <fstream>;

using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");

int main()
{
	int n,m;

	f >> n;
	for(int i=1;i<=n;i++)
		for (int j = 1; j <= n; j++)
		{
			if (i == 1)
			{
				m = n;
			}
			else if (j = 1)
			{
				m++;
			}
			else
			{
				for (int k = 2; k <= j; k++)
					if ((i / k) != 0 || (j / k) != 0)
						m++;
			}

		}
	g << m;
	f.close();
	g.close();
	return 0;


}