Program fractii;
var
 p,q,n,s: longint;
 f: text;
Begin
  assign(f,'fractii.in');
  reset(f);
  read(f,n);
  close(f);

  s:=n + (n - 1);
  p:=2;
  while p < n do Begin
    for q:= p+1 to n do
     if ((p mod q <> 0) and (q mod p <> 0)) then
       s := s + 2;
    inc(p);
  End;
  
  assign(f,'fractii.out');
  rewrite(f);
  write(f,s);
  close(f);
End.