import java.util.Scanner;

/** Error.java - Let's look at error checking in Java.
 *  In other words, verify the user's input is valid.
 */
public class Error
{
  public static void main(String [] args)
  {
    Scanner kbd = new Scanner(System.in);

    // We need to declare the input variable before, not inside, the loop!
    int n = 0;

    boolean needInput = true;
    while (needInput)
    {
      System.out.print("Enter a positive integer:  ");
      n = Integer.parseInt(kbd.nextLine());
      if (n > 0)
        needInput = false;
      else
        System.out.println("Sorry, I don't understand.  Try again.");
    }

    System.out.println("You entered " + n);
  }
}