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 TestCase
  attr_reader :x, :y
  def initialize(nums_str)
    nums_array = nums_str.split
    nums = nums_array.map{|num_str| num_str.to_i}
    @x = nums[0]
    @y = nums[1]
  end

  def ==(compared)
    if @x == compared.x && @y == compared.y
      true
    elsif
      false
    end
  end

  def solve
    if @x > @y
      @x, @y = @y, @x
    end
    puts "#{@x} #{@y}"
  end
end

termination = TestCase.new("0 0")

testCases = Array.new(0)

while true
  nums_str = gets
  testCase = TestCase.new(nums_str)
  if testCase == termination
    break
  end
  
  testCases << testCase
end

testCases.each do |testCase|
  testCase.solve
end