namespace _104._Maximum_Depth_of_Binary_Tree;


//Definition for a binary tree node.
public class TreeNode {
    public int val;
    public TreeNode? left;
    public TreeNode? right;
    public TreeNode(int val=0, TreeNode? left=null, TreeNode? right =null) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}