2. (8 points) Xiao Ming met three people, one of whom is a priest, one is a liar, and one is a madman. The priest only tells the truth, the liar only tells lies, and the madman sometimes tells the truth and sometimes lies. The first one said: "I am the madman." The second one said: "You are talking nonsense, you are not the madman!" The third one said: "Stop it, I am the madman." So, among these three people, the $\qquad$th one is the madman.