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 Scala (judge verdict: Wrong Answer)

import scala.io.Source

object Main{
  def main(args: Array[String]){
    var list = List[String]()
    for(in <- Source.stdin.getLines.toList){
      list = in :: list
    }

    for(i <- 0 until list.length){
      val arr = list(list.length - i - 1).split(Array(' ')).map(_.toInt)

      if(arr(0) != 0 && arr(1) != 0){
        if(arr(0) > arr(1)){
          println(arr(1) + " " + arr(0))
        }
        else{
          println(arr(1) + " " + arr(0))
        }
      }
    }
  }
}