import Control.Applicative

import Data.List
    (sort)
    
solve :: [Int] -> [Int]

solve xs
    = sort xs

input :: Read a => IO [a]

input
    = map read.words <$> getLine

output :: Show a => [a] -> String

output xs
    = init $ concat [show x ++ " " | x <- xs]

loop :: IO ()
    
loop
    = do
        xs <- input
        case xs of
            [0, 0]
                -> return ()
            
            _
                -> do
                    putStrLn $ output $ solve xs
                    loop
                
main :: IO ()
    
main
    = loop