CrearThread2.java

class CrearThread2 {

    public static void main(String args[]) {
    Thread t1 = new Thread(new Interna1());
    Thread t2 = new Thread(new Interna2());

    t1.start();
    t2.start();
    try {
        t1.join();
        t2.join();
    }
    catch (InterruptedException ie) { }
    }

}