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