System IO C# by API

using System;
using System.IO;
public class DirectoryCounter {
    public static void Main() {
        DirectoryInfo myDir = new DirectoryInfo(@"c:\Program Files");
        int total = CountDirectories(myDir);
        Console.WriteLine(total);
    }
    public static int CountDirectories(DirectoryInfo dir) {
        DirectoryInfo[] dirs = dir.GetDirectories();
        int count = dirs.Length;
        foreach (DirectoryInfo subDir in dirs) {
            count += CountDirectories(subDir);
        }
        return count;
    }
}