查找二叉树的最深节点。如果多个节点位于最深层，则返回最右侧的Node。(答案在描述中)

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

def findDeepestNode(root):
    maxDepth = 0
    rightMostNode = None

    def dfs(node, depth, maxDepth, rightMostNode):
        if not node:
            return

        if depth > maxDepth:
            maxDepth = depth
            rightMostNode = node

        dfs(node.left, depth + 1, maxDepth, rightMostNode)
        dfs(node.right, depth + 1, maxDepth, rightMostNode)

    dfs(root, 1, maxDepth, rightMostNode)
    return rightMostNode