#include <fstream.h>

int main(void)
{
	long int n,i,j,count=0,c=0;

	ifstream date_intrare("fractii.in");
	ofstream date_iesire("fractii.out");

	date_intrare>>n;

	count=n+n-1;
	for(i=2;i<=n;i++)
	 for(j=2;j<=i;j++)
		 if(i%j!=0)
			c++;

	count=count+ 2*c;

  date_iesire<<count;

	date_intrare.close();
	date_iesire.close();
	return 0;
}