Good job, you have finished the first part. The second part is where you have to answer the riddle. It is not so much as a riddle as merely an interesting and confusing question. Your character may RP how there thinking about what the correct answer is. Whatever your answer is, you have to explain why you think that answer is correct, whether in RP or not. You will get points if you explain why you think that your answer is correct, even if it is not.]
The sphinx spoke: "To go ahead to the last part of the maze, you must answer my question. Now, if you are ready.." The sphinx paused, then spoke the riddle. "There was once a town with just one healer. A sickness emerged in this small town and all the people got sick, except the healer. Some of them healed themselves, some of then went to the healer, but the healer only cures people who do not cure themselves. However, one day the healer got sick. So who cured the healer?"
[Remember, this question does not have a simple answer. Think of an answer, and look at the sentence carefully to see if that answer is right. And remember, explain your answer.]