Even Tree - HackerRank - study C# solution - very readable code

EvenTreestudy3.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace Solution
{
    class Solution
    {
        private static Node tree;
        private static IDictionary<int, Node> nodeMap = new Dictionary<int, Node>();

        static void Main(string[] args)
        {
            string[] counts = Console.ReadLine().Split(' ');
            int M = int.Parse(counts[1]);
            while(M-- > 0)
            {
                string[] edge = Console.ReadLine().Split(' ');
                AddEdge(int.Parse(edge[0]), int.Parse(edge[1]));
            }

            int result = Traverse(tree);
            Console.WriteLine(result);
        }

        private static int Traverse(Node node)
        {
            int result = 0;
            foreach (var child in node.Children)
            {
                result += Traverse(child);
                
                if (child.ChildCount % 2 != 0)
                {
                    result++;
                }
                else
                {
                    node.ChildCount += child.ChildCount + 1;
                }
            }

            return result;
        }

        private static void AddEdge(int v1, int v2)
        {
            if (nodeMap.ContainsKey(v1))
            {
                DoAddEdge(nodeMap[v1], v2);
            }
            else if (nodeMap.ContainsKey(v2))
            {
                DoAddEdge(nodeMap[v2], v1);
            }
            else
            {
                tree = new Node(v1);
                nodeMap[v1] = tree;
                DoAddEdge(tree, v2);
            }
        }

        private static void DoAddEdge(Node node, int v2)
        {
            var child = new Node(v2);
            node.Children.Add(child);
            nodeMap[v2] = child;
        }
    }

    class Node
    {
        internal Node(int id)
        {
            Id = id;
            Children = new List<Node>();
            ChildCount = 0;
        }

        internal int ChildCount { get; set; }
        internal IList<Node> Children { get; private set; }
        internal int Id { get; private set; }
    }
}