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

int main()
{	
	unsigned int N, nr;
	int i,j;
	ifstream f("fractii.in");
	ofstream g("fractii.out");
	
	f>>N; 
	nr=0;
	for(i=1;i<=N;i++)
	  for(j=1;j<=N;j++)
	    if((i==1 || i!=1) && (j==1 || j!=1))
	    	nr++;
	    if(i%j!=0 || j%1!=0 )
	      nr++;
				 
    
	g<<nr<<endl;
	
	f.close();
	g.close();
	return 0;
}