#include <stdio.h>
#include <iostream>
#include <fstream>
using namespace std;
int main(int argc, char *argv[])
{
	int n,k=0;
	ifstream fin("fractii.in");
	fin>>n;
	k=2*n-1;
	fin.close();
	ofstream fout("fractii.out");
	for (float i=2; i<=n; i++)
		for (float j=i+1; j<=n; j++)
			if (j/i!=int(j/i))
				k+=2;
	fout<<k<<endl;			
	fout.close();
   getchar();
   return 0;
}