Tree DFS recursion

/* Define classes File { string name, int size } and Folder { string name, File[] files, Folder[] childFolders } and using them build a tree keeping all files and folders on the hard drive starting from C:\WINDOWS. Implement a method that calculates the sum of the file sizes in given subtree of the tree and test it accordingly. Use recursive DFS traversal. */

class File
{
    public File(string name, long size)
    {
        this.Name = name;
        this.Size = size;
    }

    public string Name { get; private set; }

    public long Size { get; private set; }
}

class Folder
{
    public Folder(string name, List<File> files, List<Folder> childFolders)
    {
        this.Name = name;
        this.Files = files;
        this.ChildFolders = childFolders;
    }

    public string Name { get; private set; }

    public List<File> Files { get; private set; }

    public List<Folder> ChildFolders { get; private set; }

    public override string ToString()
    {
        return this.Name;
    }
}

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

class Program
{
    static Stack<Folder> folders = new Stack<Folder>();
    static long sum = 0;

    static void Main()
    {
        string sourceDirectory = @"C:\Windows";
        string searchedDirectory = "Cursors";

        Folder result = TraverseDirectory(sourceDirectory);

        Folder searchedFolder = GetDirectory(searchedDirectory, result);

        Console.WriteLine(searchedFolder);

        long totalSize = CalculateTotalSize(searchedFolder);

        Console.WriteLine(totalSize);
    }

    private static Folder TraverseDirectory(string sourceDirectory)
    {
        DirectoryInfo di = new DirectoryInfo(sourceDirectory);
        FileInfo[] filesInfo = di.GetFiles();
        DirectoryInfo[] directoriesInfo = di.GetDirectories();

        List<File> files = new List<File>();
        foreach (var file in filesInfo)
        {
            files.Add(new File(file.Name, file.Length));
        }

        List<Folder> directories = new List<Folder>();
        foreach (var directory in directoriesInfo)
        {
            try
            {
                directories.Add(TraverseDirectory(directory.FullName));
            }
            catch (UnauthorizedAccessException)
            {
                // Skip inaccessible directories
            }

        }

        string[] args = sourceDirectory.Split('\\');
        string name = args[args.Length - 1];
        Folder currentDirectory = new Folder(name, files, directories);

        return currentDirectory;
    }

    private static long CalculateTotalSize(Folder searchedFolder)
    {
        foreach (File file in searchedFolder.Files)
        {
            sum += file.Size;
        }
        foreach (Folder folder in searchedFolder.ChildFolders)
        {
            CalculateTotalSize(folder);
        }
        return sum;
    }

    public static Folder GetDirectory(string name, Folder tree)
    {
        GetFoldersStack(tree);
        while (folders.Count > 0)
        {
            if (folders.Peek().Name == name)
            {
                return folders.Pop();
            }
            else
            {
                folders.Pop();
            }
        }
        throw new ArgumentException("Folder not found");
    }

    private static void GetFoldersStack(Folder tree)
    {
        foreach (Folder folder in tree.ChildFolders)
        {
            folders.Push(folder);
            GetFoldersStack(folder);
        }
    }

}