public static void main(String[] args) {
Node root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.left.right = new Node(5);
root.left.right.left = new Node(7);
root.left.left.left = new Node(6);
root.right.right = new Node(8);
root.right.right.left = new Node(9);
print(root);
}
