let () =
  let s = Scanf.scanf "%s" (fun x -> x) in
  let len = (String.length s) in
  let len_bytes = Bytes.of_string (string_of_int (len - 2)) in
  let first_char = String.get s 0 in
  let last_char = String.get s (len - 1) in
  let first_char_bytes = Bytes.make 1 first_char in
  let last_char_bytes = Bytes.make 1 last_char in
  let concat_bytes = Bytes.concat
                       Bytes.empty
                       [first_char_bytes; len_bytes; last_char_bytes] in
  let ans = Bytes.to_string concat_bytes in
  Printf.printf "%s\n" ans
