text: # -*- coding:utf-8 -*-
  """
  @author: Alden
  @email: sunzhenhy@gmail.com
  @date: 2018/4/18
  @version: 1.0.0.0
  """
  
  
  class Solution(object):
      def fractionAddition(self, expression):
          """
          :type expression: str
          :rtype: str
          """
          a = b = None
          for i, v in enumerate(expression):
              pass
  
  
  if __name__ == "__main__":
      s = Solution()
      print s.fractionAddition("-1/2+1/2")
      print s.fractionAddition("-1/2+1/2+1/3")
      print s.fractionAddition("1/3-1/2")
      print s.fractionAddition("5/3+1/3")
  