# Definition for a  binary tree node

 # class TreeNode:

 #     def __init__(self, x):

 #         self.val = x

 #         self.left = None

 #         self.right = None

 class Solution:

     # @param p, a tree node

     # @param q, a tree node

     # @return a boolean

     def isSameTree(self, p, q):

         if (p is None and q is None):

             return True

         elif (p is None and q is not None) or (p is not None and q is None):

             return False

         else:

             if (p.val != q.val):

                 return False

             else:

                 return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)