let string_mapi f s =
  let len_s = String.length s in
  let rs = String.make len_s '\000' in
  let rec string_mapi' i =
    if i >= len_s then
      ()
    else (
      let c = s.[i] in
      let rc = f i c in
      rs.[i] <- rc;
      string_mapi' (i + 1))
  in
  string_mapi' 0;
  rs



let solve s =
  s
  |> string_mapi (fun i c ->
    let ic = int_of_char c in
    let ui = ic - i - 91 in
    char_of_int ((ui mod 26) + 90))

let () =
  let s = read_line () in
  solve s
  |> print_endline