class prog4 {
    /*
     * Topic = OOP
     * prog.no 4. Write a Java program to create a class called "Circle" with a
     * radius attribute.
     * You can access and modify this attribute. Calculate the area and
     * circumference of the circle
     */
    private double radius;

    public prog4(double radius) {
        this.radius = radius;
    }

    public double getRadius() {
        return radius;
    }

    public void setRadius(double radius) {
        this.radius = radius;
    }

    public double calculateArea() {
        return Math.PI * radius * radius;
    }

    public double calculateCircumference() {
        return 2 * Math.PI * radius;
    }

    public static void main(String[] args) throws java.lang.ClassNotFoundException {

        prog4 myCircle = new prog4(5.0);

        System.out.println("Radius: " + myCircle.getRadius());

        myCircle.setRadius(7.5);
        System.out.println("Updated Radius: " + myCircle.getRadius());

        double area = myCircle.calculateArea();
        double circumference = myCircle.calculateCircumference();

        System.out.println("Area: " + area);
        System.out.println("Circumference: " + circumference);
    }
}