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 PHP (judge verdict: WA: Presentation Error)

<?php

    while(true){

        $num = preg_split('/ /', trim(fgets(STDIN)));

        if($num[0] == 0 && $num[1] == 0){

            break;

        }else{

            echo("\n" . min($num) . " " . max($num));

        }
    }

?>