text: #!/usr/bin/python
  
  
  # Definition for a binary tree node.
  class TreeNode(object):
      def __init__(self, x):
          self.val = x
          self.left = None
          self.right = None
  
  class Solution(object):
      def rob(self, root):
          """
          :type root: TreeNode
          :rtype: int
          """
          
  