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: Wrong Answer)

<?php

while($input = trim(fgets(STDIN))){
    $array = explode(" ",$input);
    sort($array);
        if($array[0] != 0 && $array[1] != 0){
        print(sprintf("%d %d\n",$array[0],$array[1]));
        }
}