import Control.Applicative ((<$>))
import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Char8 as B
import Data.Char

main :: IO ()
main = putStrLn =<< solve <$> B.getLine

solve :: ByteString -> String
solve bs = map f $ B.unpack bs
    where
        f :: Char -> Char
        f a
          | isLower a = toUpper a
          | otherwise = toLower a