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: WA: Presentation Error)

import scala.collection.mutable.ListBuffer
import scala.io.StdIn

object Main extends App {
  var continue = true
  var result = ListBuffer.empty[String]
  while(continue){
    val Array(x, y) = StdIn.readLine().trim.split(' ').map(_.toInt)
    continue = if(x == 0 && y == 0) {
      false
    } else {
      result += (if(x > y) f"$y $x%n" else f"$x $y%n")
      true
    }
  }
  
  print(result.map(p => p).mkString("").dropRight(1))
}