import java.util.*;
import java.util.concurrent.*;

class ExampleThread extends Thread {
    private static CountDownLatch latch = new CountDownLatch(1);
    private static Semaphore semaphore = new Semaphore(1, true);

    private int type;
    private String[] letters = { "A", "B", "C", "D", "E" };

    ExampleThread(int type) {
        super();
        this.type = type;
    }

    public void run() {
        try {
            if (type == 0) {
                semaphore.acquire();
                latch.countDown();
            } else {
                latch.await();
                semaphore.acquire();
            }

            for (int i = 0; i < 5; i++) {
                if (type == 0) {
                    System.out.print(i);
                } else {
                    System.out.print(letters[i]);
                }
                Thread.sleep(100);
            }
        } catch (Exception ex) {
            System.out.println("Exception 2");
        }
        semaphore.release();
    }


    public static void main(String[] args) {
        new ExampleThread(1).start();
        new ExampleThread(0).start();
    }
}