1     public abstract class GBElectricalAppliance
2     {
3         public abstract void Input(int left, int right);
4     }

 1     public class OutPut
 2     {
 3         public OutPut()
 4         {
 5             this.EACollection = new List<GBElectricalAppliance>();
 6         }
 7         private List<GBElectricalAppliance> EACollection;
 8         public void powered(int left,int right)
 9         {
10             foreach (var item in EACollection)
11             {
12                 item.Input(left,right);
13             }
14         }
15         public void AddInput(GBElectricalAppliance item)
16         {
17             EACollection.Add(item);
18         }
19
20         public void RemoveInput(GBElectricalAppliance item)
21         {
22             EACollection.Remove(item);
23         }
24     }

 1     public class TV : GBElectricalAppliance
 2     {
 3         public override void Input(int left, int right)
 4         {
 5             Show();
 6             Sound();
 7         }
 8
 9         private void Show()
10         {
11             Console.WriteLine("I am showing");
12         }
13         private void Sound()
14         {
15             Console.WriteLine("I am sounding");
16         }
17     }
18
19     public class ElectricKettle : GBElectricalAppliance
20     {
21         public override void Input(int left, int right)
22         {
23             Heat();
24         }
25
26         private void Heat()
27         {
28             Console.WriteLine("I am heating");
29         }
30     }