#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");

int main()
{
   unsigned int N;
   int p,r,i,cont=0;
   fin>>N;
   if(N>=1&&N<=1000000)
   {cont+=N;
   cont+=N-1;
   for(p=2;p<=N;p++)
   {
       for(r=2;r<=N;r++)
       {
           if(p%r&&r%p)
            cont++;
       }
   }
   fout<<cont;
   }
   fin.close();
   fout.close();

}