new_contents: #!/usr/bin/env python
  # encoding: utf-8
  
  class Solution:
      # @param {integer[]} nums
      # @return {integer}
      def rob(self, nums):
          if not nums:
              return 0
          
          a, b = 0,0
          for i, n in enumerate(nums):
              if i%2:
                  a = max(a+n, b)
              else:
                  b = max(b+n, a)
                  
          return max(a,b)
  
subject: Add houst robber