Context: New England, the late 1950s. Todd Anderson (Ethan Hawke), a lonely and painfully shy teenager, who is under pressure by his stern parents because he must live up to his older brother's reputation to attend Yale and become a lawyer, arrives for the new semester at the Welton Academy for boys -- Todd's brother also attended Welton and was a popular and well-regarded student there. This semester begins during an orientation gathering with a speech given by the stern Headmaster Nolan (Norman Lloyd), who states the academy's four pillars: Tradition, Honor, Discipline, and Excellence. Todd meets Neil Perry (Robert Sean Leonard) an ambitious student whom becomes his dorm roommate.Later in his dorm, Neil is ordered by his grumpy and domineering father (Kurtwood Smith) to drop his involvement with the school annual in order to maintain good grades so the boy may become a doctor much as he has done. Neil is under pressure from his stern father's will. Also, Mr. Perry tells Neil that Mrs. Perry also wants him to become a doctor, which further worries the boy. A little later, Todd tells Neil that he is in a similar situation with his parents involving his older brother who also attended Welton a few years ago, graduated, and attended Yale Law School and became a lawyer and his parents want the exact same thing for him. But Todd does not have the courage to tell his parents that he instead wants to be a writer, not a lawyer.During the first day of classes Todd and Neil experience the various teaching methods which include speeches by the trig teacher, as well as the Latin teacher, and the math teacher who states that "all 20 questions at the end of the first chapter are due tomorrow". In stark contrast to these orthodox teaching methods, the guys see a different side of the school when they attend English class taught by the newly arrived (and liberal-minded) Mr. Keating (Robin Williams), whom they met briefly during the orientation -- Keating tells his class he was also a student at Welton ("Helton" as the students secretly refer to the institution) himself many years ago. Keating enters his class whistling the 1812 Overture, and he first takes the boys out in the hallway to the school's displays cases containing artifacts of the school's sports achievements. He tells them that they all have the potential to become powerful individuals, and they are responsible for what their futures will hold. These two actions show his difference from the other teachers because no other teacher would commit the actions he does. Also, he tells the boys they may call him "Oh Captain, my Captain", if they dare. These examples of Mr. Keating's teachings show the boys how to think for themselves. Mr. Keating then tells the boys "Carpe Diem", which is Latin for "seize the day".In addition to Todd and Neil, a small group of other students whom include the lovesick Knox Overstreet (Josh Charles), the flip Charlie Dalton (Gale Hansen), the pragmatic Richard Cameron (Dylan Kussman), liberal Steven Meeks (Allelon Ruggiero) and the moderate Gerard Pitts (James Waterston), also react to the first day's lesson with comments from "that was weird" to "neat". Cameron asks if anything Keating told them will be on a future test and the boys respond with mild scorn.The next day Keating starts the class with a traditional teaching approach by having Neil read out loud the introduction to their poetry textbook, which describes how to rate the quality of poetry according to mathematical plotting. Keating finds such mathematical criticism ridiculous and instructs his pupils to rip out the essay which is one of three ways that he demonstrates freedom of expression and non-conformity. When some students hesitate, he tells them "this is not the Bible. This is a battle, a war. You will have to learn to think for yourselves." He later has the students stand on his desk as a reminder to look at the world in a different way.A few days later, Knox Overstreet is asked to attend a dinner party at the Danburry 
 Question: Who takes over Keating's class?
Output: headmaster nolan