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)

f :: [[Int]] -> IO()
f ([0,0]:_) = return ()
f ([x,y]:r) = do 
    putStrLn $ if(x < y) then (show x) ++ " " ++ (show y) else (show y) ++ " " ++ (show x) 
    f r

main = getContents >>= f . map (map read) . (map words) . lines