FunnySum for a Desk Check Example

/**
 *
 * Purpose: This funny number summer sums numbers in a funny way, and it's meant
 * to provide an example of how to desk check a program.
 *
 *
 * @author James P. Burke
 *
 */

public class FunnySum {

/**
 * The main method sums some numbers and outputs some progress along the way.
 * @param args
 */
    public static void main(String[] args) {

        int a;
        int x = 0;
        int y = 0;
        int r = 0;
        while (x < 10) {
            a = x * 2;
            r = a % 3;  // r is set to the remainder of a divided by 3
            switch (r) {
            case 0:
                y += a;
                System.out.println(a + " must be divisible by three!");
                break;
            case 1:
                y += x;
                break;
            case 2:
                y += r;
                break;
            default:
                System.out.println("We should never actually get here.");
                break;
            }
            x ++;
        }
        System.out.println("The sum is " + y);
    }

}