output_description: For each dataset, print x and y in ascending order in a line. Put a single
  space between x and y.
input_description: 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.
attempt: def get_input():
      lst = []
      pair = [int(n) for n in input().split(" ")]
      while pair != [0, 0]:
          lst.append(pair)
          pair = [int(n) for n in input().split(" ")]
      return lst
  
  
  def to_str(lst):
      return [str(n) for n in lst]
  
  
  lst = get_input()
  for pair in lst:
      print(" ".join(to_str(sorted(pair))))
  
problem_description: Swapping Two Numbers
  
  Write a program which reads two integers x and y, and prints them in ascending
  order.
samples: [{"input": "2\n    2 2\n    5 3\n    0 0", "output": "3\n    2 2\n    3 5"}]