import java.util.Scanner;

class Shape {
    double calculateArea(double a) {
        return 0;
    }

    double calculateArea(double a, double b) {
        return 0;
    }
}

class Circle extends Shape {
    @Override
    double calculateArea(double radius) {
        return Math.PI * radius * radius;
    }
}

class Rectangle extends Shape {
    @Override
    double calculateArea(double length, double width) {
        return length * width;
    }
}

class Square extends Shape {
    @Override
    double calculateArea(double side) {
        return side * side;
    }
}

public class AreaCalculator {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String shapeType = sc.nextLine();

        Shape shape=new Shape();
        double area = 0.0;

        switch (shapeType) {
            case "Circle":
                double radius = sc.nextDouble();
                if(radius<0){
                    System.out.println("Invalid input");
                    return;
                }
                shape = new Circle();
                area = shape.calculateArea(radius);
                break;

            case "Rectangle":
                double length = sc.nextDouble();
                 if(length<0){
                    System.out.println("Invalid input");
                    return;
                }
                double width = sc.nextDouble();
                 if(width<0){
                    System.out.println("Invalid input");
                    return;
                }
                shape = new Rectangle();
                area = shape.calculateArea(length, width);
                break;

            case "Square":
                double side = sc.nextDouble();
                 if(side<0){
                    System.out.println("Invalid input");
                    return;
                }
                shape = new Square();
                area = shape.calculateArea(side);
                break;

            default:
                System.out.println("Invalid input");
                return;
        }

        System.out.printf("%.2f\n", area);
    }
}


/*
// editor1 vishnus program
import java.util.*;
abstract class Shape{
   
    abstract void area();
   
}
class Circle extends Shape{
    private double radius;
    Circle(double radius){
        this.radius=radius;
    }
    @Override
    void area(){
        System.out.printf("%.2f",Math.PI *radius*radius);
    }
}
class Rectangle extends Shape{
    private double length;
    private double breadth;
    Rectangle(double length,double breadth){
        this.length=length;
        this.breadth=breadth;
    }
    @Override
    void area(){
        System.out.printf("%.2f",length*breadth);
    }
}
class Square extends Shape{
    private double side;
    Square(double side){
        this.side=side;
    }
    @Override
    void area(){
        System.out.printf("%.2f",side*side);
    }
}
class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        String s=sc.nextLine();
        if(s.equals("Circle")){
           
            double radius=sc.nextDouble();
            if(radius<0){
            System.out.print("Invalid input");
            return;
            }
            Circle c=new Circle(radius);
            c.area();
        }else if(s.equals("Rectangle")){
            double length=sc.nextDouble();
            double breadth=sc.nextDouble();
            if(length<0||breadth<0){
                System.out.print("Invalid input");
                return;
            }
            Rectangle r=new Rectangle(length,breadth);
            r.area();
        }else if(s.equals("Square")){
            double side=sc.nextDouble();
            if(side<0){
                System.out.print("Invalid input");
                return;
            }
            Square s2=new Square(side);
            s2.area();
        }else{
            System.out.print("Invalid input");
        }
    }
}*/