using System;

public class Box

{

  public int Height { get; set; }

  public int Width { get; set; }

  public Box(int h, int w)

  {

    Height = h;

    Width = w;

  }

  public static Box operator +(Box box1, Box box2)

  {

    int h = box1.Height + box2.Height;

    int w = box1.Width + box2.Width;

    Box result = new Box(h, w);

    return result;

  }

}

​

public class Program

{

  public static void Main()

  {

    Box b1 = new Box(14, 3);

    Box b2 = new Box(5, 7);

    Box b3 = b1 + b2;

    Box b4 = b1 + b2 + b3;

    Console.WriteLine("Box b1: Height: {0}, Width: {1}", b1.Height, b1.Width);

    Console.WriteLine("Box b2: Height: {0}, Width: {1}", b2.Height, b2.Width);

    Console.WriteLine("Box b3: Height: {0}, Width: {1}", b3.Height, b3.Width);

    Console.WriteLine("Box b4: Height: {0}, Width: {1}", b4.Height, b4.Width);

  }

}