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: Accepted)

<?php
while (true) {
    $input = trim(fgets(STDIN));
    $ary = sscanf($input, "%d %d");
    if ($ary[0] == 0 && $ary[1] == 0) {
        break;
    } else {
        asort($ary);
        echo implode(" ", $ary).PHP_EOL;
    }
}