using System;

public class Program

{

    public interface Command 

    {

        void Execute();

    }

    public class Remote

    {

        const int PRESSED = 0;

        const int NOT_PRESSED = 1;

        Command[] _command;

        public Command[] Command 

        {

            set { _command = value; }

        }

        public void OnButtonWasPressed()

        {

            _command[PRESSED].Execute();

        }

        public void OffButtonWasPressed()

        {

            _command[NOT_PRESSED].Execute();            

        }

    }

    public class Light {

        public string On() 

        {

            return "Light is on!";

        }

        public string Off()

        {

            return "Light is off";

        }

    }

    public class LightOnCommand : Command

    {

        private Light _light;

        public LightOnCommand(Light light)

        {

            _light = light;

        }

        public void Execute() { Console.WriteLine(_light.On()); }

    }

    public class LightOffCommand : Command

    {

        private Light _light;

        public LightOffCommand(Light light)

        {

            _light = light;

        }

        public void Execute() { Console.WriteLine(_light.Off()); }

    }

    public static void Main()

    {

        Light light = new Light();

        LightOnCommand lightCommand = new LightOnCommand(light);

        LightOffCommand lightOffCommand = new LightOffCommand(light);

        Remote remote = new Remote();

        remote.Command = new Command[] { lightCommand,lightOffCommand };

        remote.OnButtonWasPressed();

        remote.OffButtonWasPressed();

    }

}