# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
if (p.val < root.val and q.val >= root.val) or (p.val >= root.val and q.val < root.val):
return root
if p.val <= root.val and q.val <= root.val:
if root.val == p.val or root.val == q.val:
return root
return self.lowestCommonAncestor(root.left, p, q)
else:
if root.val == p.val or root.val == q.val:
return root
return self.lowestCommonAncestor(root.right, p, q)