package q104

type TreeNode struct {
	Val   int
	Left  *TreeNode
	Right *TreeNode
}

func md(d int, node *TreeNode) int {
	if node == nil {
		return d - 1
	}
	return max(md(d+1, node.Left), md(d+1, node.Right))
}

func maxDepth(root *TreeNode) int {
	return md(1, root)
}

var _ = maxDepth