A girl was walking on the side walk. She sees a man lying on the street, needing immediate help. The victim says that he is having a heart attack. The girl asks people around the street. And a man approached.
Girl: Help, are you a doctor?
Man: I am a doctor. What's going on?
Girl: A Heart Attack!
Man: I am doctor in mathematics.
Girl: He is going to die.
Man: Prove it!
#joke