using System;

class MainClass
{
    public static void Run()
    {
        var f = new Foo2();
        f.Method(1);
        ((Foo)f).Method(1);
    }
}

static class FooExtensions
{
    public static void Method(this Foo foo, int param1)
    {
        Console.WriteLine("FooExtensions.Method");
    }
}

class Foo
{
    public void Method(long param1) { Console.WriteLine("Foo.Method"); }
}

class Foo1 : Foo
{
    public new Action Method = () => Console.WriteLine("Foo1.Method");
}

class Foo2 : Foo1
{
    new public void Method() { Console.WriteLine("Foo2.Method"); }
}