var i,j,n,nr:longint;
begin
 assign(input,'fractii.in');reset(input);
 assign(output,'fractii.out');rewrite(output);
 read(n);
  for i:=1 to n do
   begin
    for j:=1 to n do
     begin
      if (i mod j<>0) then
       begin
        inc(nr);
       end;
     end;
   end;
   write(nr+1);
end.