using System;

public class Program

{

    class Rectangle

     {

        private double length;

        private double width;

       public Rectangle (double length, double width)

       {    

            this.length = length;

            this.width = width;

       }

        public void AddToLength(double x)

        {        

            this.length += x;

        }        

       public double CalcArea()

       {       

            return (this.length * this.width);

       }       

       public double HIKEF()

       {

         return (this.length + this.width + this.length + this.width);

       }

}

public static void Main()

{

Rectangle r1 = new Rectangle (2.5 , 6.0);

Rectangle r2 = new Rectangle (3.0 , 7.5);

​

for (int i=0; i<3; i++)

{

if (i % 2 == 0)

   r1.AddToLength(1.0);

 else 

    r2.AddToLength(2.0);

​

    Console.WriteLine(r1.CalcArea());

    Console.WriteLine(r2.CalcArea());

    Console.WriteLine("S:"+r1.HIKEF());

    Console.WriteLine("S:"+r2.HIKEF());

​

} 

}

}