I posted a question half a hour ago. But I think I found the answer myself now. I understand that answering your own question is appreciated (instead of deleting it). But I don't know if I should give a hint or a full solution.
It feels a little bit strange to give a hint to my own question, I don't know, it is like I'm trying to teach myself :P
On the other hand, if someone is ever searching for this question (and it is a question from a popular book, so I think there is a good chance he/she will find this question), then you could argue that it is better to give a hint instead of a full solution.