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($input_line = trim(fgets(STDIN))){

        $num = explode(" ",$input_line);
        if($num[0]==0 && $num[1]==0){
            break;
        }
        if($num[0]>$num[1]){
            $z =$num[1];
            $num[1] = $num[0];
            $num[0] = $z;
        }
        
        echo $num[0];
        echo " ";
        echo $num[1];
        echo "\n";
    }
?>