using System;
class a
{
    public virtual event EventHandler MyEv;
    public void StartEvent()
    {
        MyEv(4, EventArgs.Empty);
    }
}
class b : a
{
    public override event EventHandler MyEv;
}
class c
{
    static void Main()
    {
        b B = new b();
        B.MyEv += (o, e) => Console.WriteLine("From class B");
        B.StartEvent();
    }
}