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
$a = [];
while(true)
{
    $in = explode(" ", trim(fgets(STDIN)));
    if($in[0] == 0 && $in[1] == 0)
    {
        break;
    }
    else
    {
        $a[] = $in;
    }

}
for($i = 0; $i < count($a); $i++)
{
    if($a[$i][0] > $a[$i][1])
    {
        echo $a[$i][1] . " " . $a[$i][0] . "\n";
    }
    else
    {
        echo $a[$i][0] . " " . $a[$i][1] . "\n";
    }
}