Let me tell u a joke about a teacher being cheat by a student.
A teacher said if anyone could get him to leave the classroom,he would reward that person.A student said to the teacher''teacher, i cannot get you to leave the room but if you go out of the room i can get you to come in."So, the teacher went out of the room and said''prove it to me."The student said,"see,i got you to leave the room!'the teacher had no choice but to reward him.