#include <fstream>
#include <iostream>
using namespace std;

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