# 104. Maximum Depth of Binary Tree
# https://leetcode.com/problems/maximum-depth-of-binary-tree

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
  def maxDepth(self, root: Optional[TreeNode]) -> int:
    return 1 + max(map(self.maxDepth, (root.left, root.right))) if root else 0