var i, j, sum, n:integer;
    f, g:text;

function divizor(x:integer):integer;
var cat, ii:integer;
  begin
  cat:=0;
  for ii := 2 to x div 2 do if x mod ii = 0 then cat:=cat+1;
  divizor:=cat;
  end;

begin
assign (f, 'fractii.in'); reset (f);
assign (g, 'fractii.out'); rewrite (g);
read (f, n);
sum:=n;
for i := 2 to n do
  begin
  sum := sum + n;
  sum := sum - divizor(i);
  sum := sum - (n div i);
  end;

write (g, sum);

close (f); close (g);
end.