fun readStr () =
    valOf (TextIO.inputLine TextIO.stdIn)


val () =
    let
        val s = readStr ()
        
        fun turnOnCapsLock str =
            String.implode (map (fn c => if Char.isLower c then Char.toUpper c else Char.toLower c) (String.explode str))

        val ans = turnOnCapsLock s
    in
        print ans
    end