using System;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            new MyClass.MyClass2.MyClass3().SayHello();
        }

    }
}

internal class MyClass
{
    public class MyClass2
    {
        public class MyClass3
        {
            public void SayHello()
            {
                Console.WriteLine("Hello!");
            }
        }
    }
}