# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
#
# 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
#
# 
# @param root TreeNode类 
# @param o1 int整型 
# @param o2 int整型 
# @return int整型
#
class Solution:
    def lowestCommonAncestor(self , root: TreeNode, o1: int, o2: int) -> int:
        if (not root) or (root.val == o1) or (root.val == o2):
            return root and root.val
         
        left = self.lowestCommonAncestor(root.left, o1, o2)
        right = self.lowestCommonAncestor(root.right, o1, o2)
         
        if left and right: return root.val
        if left: return left
        return right or None