import Prelude
import Data.Char (toLower, toUpper)

main :: IO ()
main = getLine >>= putStrLn . calc

calc :: String -> String
calc = map capsLock
  where
    capsLock :: Char -> Char
    capsLock c | elem c ['A'..'Z'] = toLower c
    capsLock c | elem c ['a'..'z'] = toUpper c
    capsLock c = c