So, the idea here is that if we have ~p and ~q at the same time, that's correct.

Otherwise, we return false.

And, if any values don't match as we recursively iterate --> we also return false.

Hopefully this presents what's going on in an easy to understand way.

```
# 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 isSameTree(self, p, q):
"""
:type p: TreeNode
:type q: TreeNode
:rtype: bool
"""
# base cases
if not p and not q:
return True
elif not p:
return False
elif not q:
return False
# recursive case
return p.val == q.val and \
self.isSameTree(p.left, q.left) and \
self.isSameTree(p.right, q.right)
```