let chr_to_num c = Char.code c - Char.code '0'

let num_to_chr n = Char.code '0' + n |> Char.chr

let print_char_n c n = for i = 0 to n - 1 do print_char c done

let () =
  let t = Array.make 10 0 in
  read_line ()
  |> String.iter (fun c -> let n = chr_to_num c in t.(n) <- t.(n) + 1);
  for i = 9 downto 0 do
    print_char_n (num_to_chr i) t.(i);
  done;
  print_newline ()