Assume there are n students in the class. Each student is assigned a seat labeled from 1 to n. The students walk into the classroom according to their seat numbers, i. e., the student assigned seat 1 walks in first and n last. If a student finds the seat assigned to him is occupied, he will select a seat from currently empty seats uniformly at random. If the first student forgets his seat number, which means the student will select a seat from all empty seats uniformly at random, what is the probability that the nth student still sits in his seat?