defmodule Main do
  def main do
    IO.read(:line)
    |> String.trim()
    |> solve
    |> IO.puts()
  end

  defp solve(str) do
    str
    |> String.to_charlist()
    |> Enum.with_index()
    |> Enum.map(fn {s, i} ->
      alphabet()
      |> Enum.at(
        (Enum.find_index(alphabet(), &(&1 == s)) - i - 1)
        |> rem(26)
      )
      |> (&([&1])).()
    end)
    |> Enum.join()
  end

  defp alphabet do
    ?A..?Z
    |> Enum.map(&([&1]))
    |> Enum.join()
    |> String.to_charlist()
  end
end