import java.text.DecimalFormat;	// p.32
import java.util.Scanner;

class CircleValueLoop
{
	public static void main(String[] args)
	{
		DecimalFormat f = new DecimalFormat("0.0");
		Scanner input = new Scanner(System.in);
		double radius, area;
		boolean go = true;
		String answer;

		while(go)
		{
			System.out.print("Please input radius: ");
			radius = input.nextDouble();

			//System.out.println("The radius is: " + radius);

			area = Math.PI * radius * radius;

			System.out.println("The area is " + f.format(area) + "\n\n");

			System.out.print("Quit (yes/no): ");
			answer = input.next();
			if(answer.equalsIgnoreCase("yes"))
				go = false;
		}

		System.out.println("\n\nDone.\n\n");
	}
}