let string_1_list_of_string x =
  String.to_seq x
  |> List.of_seq
  |> List.map (String.make 1);;

let rec asshuku n s =
  match n with
  | 0 -> s
  | _ ->
    let s = string_of_int s
            |> string_1_list_of_string
            |> List.map int_of_string in
    asshuku (n - 1) (List.fold_left (+) 0 s);;

let () =
  let s = read_line () |> int_of_string in
  asshuku 100 s |> print_int; print_newline ();;