loop :: () -> IO ()
loop = do
  [x, y] <- fmap ( read :: String -> Int).words <$> getLine
  if x == 0 && y == 0 
    then return ()
    else do 
      putStrLn $ swap $ x y
      

swap :: Int -> Int -> String
swap x y | x > y = show x ++ " " ++ show y
         | otherwise = show y ++ " " + show x
  