#include <bits/stdc++.h>

using namespace std;
ifstream in("fractii.in");
ofstream out("fractii.out");
int Cmmdc(int p, int q)
{
  int r;
  while(q != 0)
  {
    r = p % q;
    p = q;
    q = r;
  }
  return p;
}

int main()
{
    int p, q, n, s;
    in >> n;
    s = 2 * n - 1;
    for(p = 2; p <= n; p++)
     for(q = 2; q <=p; q++)
      {
        if((p != q) && (Cmmdc(p, q) == 1))
          s += 2;
      }
   out << s << "\n";
   in.close();
   out.close();
    return 0;
}