// This is the interface that allows for creating nested lists. // You should not implement it, or speculate about its implementation public interface

Definition for singly-linked list. class ListNode { int val; ListNode next; ListNode(int x) { val = x; next = null; }

Definition for a binary tree node. public class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; } }

Definition for a binary tree node. public class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; } }