public void run() {
   try {
     while (true) {
       monArb.entrarLeer(currentThread());
       monArb.entrarLeer(currentThread());
       Thread.sleep(3500);
       if (Math.random() < 0.5) Thread.sleep(2500);
       System.out.println("Reader " + currentThread().getId() + " reads " + baseDatos.leer());
       monArb.salirLeer(currentThread());
     }
   } catch (InterruptedException e) {
   }
 }