//RadiusCalculator calculates the area of a circle given an integer value 


import java.io.*;

class RadiusCalculator {
        static final double PI_VALUE=3.14159;

        public static void main (String args[]) throws IOException
        {
        BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
        
        String string1;;
        int radius;
        double area;
        System.out.println("Enter a whole number:");
        string1=stdin.readLine();
        radius= Integer.parseInt(string1);

        
        System.out.println("The area is " + (PI_VALUE*(radius*radius)));

        }//main method
}//RadiusCalculator class