loopPutNumbers :: IO ()
loopPutNumbers = do
    [x,y] <- map (read :: String -> Int) . words <$> getLine
    Monad.when (x /= 0 || y /= 0) $ do
        putStrLn $ if (x < y)
                    then unwords $ show <$> [x,y]
                    else unwords $ show <$> [y,x]
        loopPutNumbers
loopPutNumbers :: IO ()
loopPutNumbers = do
    [x,y] <- map (read :: String -> Int) . words <$> getLine
    Monad.when (x /= 0 || y /= 0) $ do
        putStrLn $ if (x < y)
                    then unwords $ show <$> [x,y]
                    else unwords $ show <$> [y,x]
        loopPutNumbers
loopPutNumbers = do
    [x,y] <- map (read :: String -> Int) . words <$> getLine
    Monad.when (x /= 0 || y /= 0) $ do
        putStrLn $ if (x < y)
                    then unwords $ show <$> [x,y]
                    else unwords $ show <$> [y,x]
        loopPutNumbers