Problem:
Swapping Two Numbers

Write a program which reads two integers x and y, and prints them in ascending order.

Input

The input consists of multiple datasets. Each dataset consists of two integers x and y separated by a single space.

The input ends with two 0 (when both x and y are zero). Your program should not process for these terminal symbols.

Output

For each dataset, print x and y in ascending order in a line. Put a single space between x and y.

Constraints

0 ≤ x, y ≤ 10000

the number of datasets ≤ 3000

Sample Input

3 2
2 2
5 3
0 0

Sample Output

2 3
2 2
3 5

Solution in Haskell (judge verdict: Accepted)

import Data.List
main =
  getContents >>=
    mapM_ putStrLn
    . map (unwords . map show . sort . map (read :: String -> Int) . words)
    -- . map ((\xs -> if xs!!0 < xs!!1 then xs!!0 ++ " " ++ xs!!1 else xs!!1 ++ " " ++ xs!!0) . words)
    . init . lines