text: import sys
  
  def main():
    # input
    num, i = [], 0
    while True:
      num.append(list(map(int, input().split())))
      if num[i] == [0, 0]:
        break
      i += 1
  
    # output
    for i in range(len(num)-1):
      if num[i][0] > num[i][1]:
        num[i][0], num[i][1] = num[i][1], num[i][0]
      print(num[i][0], num[i][1])
  
  
  if __name__ == "__main__":
      main()
  