fun readChar () =
    valOf (TextIO.scanStream Char.scan TextIO.stdIn)

exception BadInput
val () =
    let
        val s = readChar ()

        val ans = case s of
                      #"A" => "A#"
                    | #"C" => "C#"
                    | #"D" => "D#"
                    | #"F" => "F#"
                    | #"G" => "G#"
                    | #"E" => "F"
                    | #"B" => "C"
                    | _ => raise BadInput
    in
        print (ans ^ "\n")
    end