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: f = "{} {}\n".format
  open(1, "w").writelines(
      [f(*sorted(map(int, line.split()))) for line in open(0).readlines()][:-1]
  )
  
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"}]