program fractii;
var n,nf:int64;
    a,b,i,j:longint;
    f,g:text;
begin
  assign(f,'fractii.in');
  assign(g,'fractii.out');
  reset(f);
  rewrite(g);
  readln(f,n);
  nf:=n*2;
  for a:=2 to n do
    for b:=2 to n do
      begin
        if b >a then
          i:=b
        else
          i:=a;
        if b >a then
          j:=a
        else
          j:=b;
        if i mod j<>0 then
          nf:=nf+1;
      end;
  writeln(g,nf-1);
  close(f);
  close(g);
end.