/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p == null || q == null){
            if(p== null && q == null){
                return true;
            }else return false;
        }
        return p.val == q.val &&isSameTree(p.left,q.left)&&isSameTree(q.right,p.right);
    }
}

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public int maxDepth(TreeNode root) {
        if(root == null) return 0;
        if(root.left == null && root.right == null) return 1;
        int DL = maxDepth(root.left);
        int DR = maxDepth(root.right);
        return (DL>DR?DL:DR)+1;
        
    }
}