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 Control.Applicative

swap [x,y] | x > y = [y,x]
swap [x,y]         = [x,y]

main = do
    ss <- words <$>getLine
    let x:y:_ = swap $ take 2 [ read s | s <- ss]
    
    if x+y>0 then do
      putStrLn $ show x ++ " " ++ show y
      main
    else return()