// CS0239.cs
abstract class MyClass
{
   public abstract void f();
}

class MyClass2 : MyClass
{
   public static void Main()
   {
   }

   public override sealed void f()
   {
   }
}

class MyClass3 : MyClass2
{
   public override void f()   // CS0239
   // Try the following definition instead:
   // public new void f()
   {
   }
}