What will be the output of the program?

public class Test  {      public static void main(String[] args)      {         final StringBuffer a = new StringBuffer();          final StringBuffer b = new StringBuffer();           new Thread()          {              public void run()              {                 System.out.print(a.append("A"));                  synchronized(b)                  {                      System.out.print(b.append("B"));                  }              }          }.start();                       new Thread()          {             public void run()              {                 System.out.print(b.append("C"));                  synchronized(a)                  {                     System.out.print(a.append("D"));                  }              }          }.start();      }  }