import java.util.*;
interface Area {
    double calculateArea();
}
class Circle implements Area {
    double radius;
    Circle(double r) {
        radius = r;
    }
    public double calculateArea() {
        return 3.14 * radius * radius;
    }}
public class Main2 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter radius of the circle: ");
        double r = sc.nextDouble();
        Circle c = new Circle(r);
        double area = c.calculateArea();
        System.out.println("Area of Circle = " + area);
    }}