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 Ruby (judge verdict: Accepted)

class Main
  def self.run
    data_set = read_inputs
    data_set.map{|xy| xy.sort.join(" ")}.each{|answer| puts answer}
  end

  private

  def self.read_inputs
    data_set = []
    while true do
      xy = gets.split(" ").map(&:to_i)
      case xy
        when [0, 0] then break
        else data_set << xy
      end
    end
    data_set
  end
end

Main.run