static void Main(string[] args)
{
Duck duck = new MallardDuck();
duck.Dance();
duck = new RedHeadDuck();
duck.Dance();
duck = new RubberDuck();
duck.Dance();
duck = new DecoyDuck();
duck.Dance();
duck = new MallardDuck();
duck.Fly();
duck.Fly();
duck.SetFlightBehaviour(new FlyWithWings());
duck.Fly();
}