import java.io.*;

/**

* 这个类演示了文档注释

* @author Ayan Amhed

* @version 1.2

*/

public class SquareNum {

   /**

   * This method returns the square of num.

   * This is a multiline description. You can use

   * as many lines as you like.

   * @param num The value to be squared.

   * @return num squared.

   */

   public double square(double num) {

      return num * num;

   }

   /**

   * This method inputs a number from the user.

   * @return The value input as a double.

   * @exception IOException On input error.

   * @see IOException

   */

   public double getNumber() throws IOException {

      InputStreamReader isr = new InputStreamReader(System.in);

      BufferedReader inData = new BufferedReader(isr);

      String str;

      str = inData.readLine();

      return Double.valueOf(str.toString());

   }

   /**

   * This method demonstrates square().

   * @param args Unused.

   * @exception IOException On input error.

   * @see IOException

   */

   public static void main(String args[]) throws IOException

   {

      SquareNum ob = new SquareNum();

      double val;

      System.out.println("Enter value to be squared: ");

      val = ob.getNumber();

      val = ob.square(val);

      System.out.println("Squared value is " + val);

   }

}