using System;

public class Program

{

    public class TreeNode 

    {

        public int val;

        public TreeNode left;

        public TreeNode right;

        public TreeNode(int val) 

        {

            this.val = val;

        }

    }

    public static int Count;

    public static int ShareCoins(TreeNode root) {

        Count = 0;

        Traverse(root);

        return Count;

    }

    public static int Traverse(TreeNode node)

    {

        if (node == null)

            return 0;

​

        int left = Traverse(node.left);

        int right = Traverse(node.right);

​

        Count += Math.Abs(left) + Math.Abs(right);

​

        return node.val + left + right - 1;

    }

    public static void Main()

    {

        Console.WriteLine("UniLecs");

        // tests

        var root1 = new TreeNode(3);

        root1.left = new TreeNode(0);

        root1.right = new TreeNode(0);

        Console.WriteLine(ShareCoins(root1).ToString()); // 2

        var root2 = new TreeNode(0);

        root2.left = new TreeNode(3);

        root2.right = new TreeNode(0);

        Console.WriteLine(ShareCoins(root2).ToString()); // 3

    }

}