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(sort)

main :: IO ()
main = myPrint . map (sort . map read . words) . lines =<< getContents

myPrint :: [[Int]] -> IO ()
myPrint [[0, 0]] = return ()
myPrint [] = return ()
myPrint (x:xs) = do
    putStrLn . unwords . map show $ x
    myPrint xs