class Exercise11 {
  public void Ex11() {
    BinaryTree<Integer> t1 = new BinaryTree<Integer>(2);
    t1.attachLeft(5);
    t1.attachRight(3);

    BinaryTree<Integer> t2 = new BinaryTree<Integer>(8);
    t2.attachLeft(6);
    t2.attachRight(7);

    BinaryTree<Integer> s = new BinaryTree<Integer>(9, t1, t2);
    BinaryTree<Integer> r = new BinaryTree<Integer>(1);
    r.attachLeft(2);
    r.attachRight(3);

    BinaryTree<Integer> t = new BinaryTree<Integer>(4, s, r);
  } // end Ex11 
} // end Exercise 11