public class Circle {

   private double diameter;  // The diameter of the circle

   // Default Constructor
   public Circle() {
      diameter = 10.0;
   }

   // Constructor
   public Circle(double r) {
      diameter = r;
   }

   // Make the circle bigger "factor" cm.
   // The new diameter of the circle is returned.
   public double grow(double factor) {
      diameter = diameter + factor;
      return diameter;
   }

   // Shrink the circle by "factor" units.
   // The new diameter of the circle is returned.
   public double shrink(double factor) {
      diameter = diameter - factor;
      return diameter;
   }

   // Access the diameter of the circle
   // without modifying it
   public double getDiameter() {
      return diameter;
   }

   // Calculate the circumference of the circle
   public double calculatetCircumference() {
      double PI = 3.14;
      return diameter*PI;
   }

   // Tell us how big the cirlce is!
   public String toString() {
      return "The diameter of this circle is " + diameter + " cm.";
   }
}