Given the task definition and input, reply with output. In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: Nathan Ellis, a 9-year-old maths prodigy, has just lost his father in a car accident. Nathan is diagnosed with autism early in the film, and his father was the only one who was able to connect normally with him. Although Nathan values his mother, Julie, he shuns any physical contact with her and treats her as more of a caretaker than a parent. Wanting to make sure Nathan isn't distracted from his studies, Julie enrolls him in advanced classes at a new school. There, he comes under the tutelage of teacher Martin, also a math genius, who now suffers from multiple sclerosis. Martin sees himself in Nathan, once a promising young mind in the field of mathematics, who gave it all up once he was diagnosed with his illness.
Seven years later, Martin is preparing Nathan to compete for a place in the International Mathematical Olympiad, a prestigious high school competition consisting of the world's best young mathematicians. This year, it is to be held at Cambridge, after a two-week math camp in Taiwan where the students will study for the test that determines the winners. Nathan fears he's not good enough to qualify but ends up doing well enough to accompany 15 other British teenagers to Taiwan.
Suddenly thrust out of his comfort zone, Nathan finds himself no longer the smartest math whiz in the room, and his social anxieties nearly paralyze his performance. He has trouble reading the social cues of others and flinches at the slightest physical contact with another person. Nathan is paired with a female Chinese student, Zhang Mei, who slowly helps him adjust to his new surroundings and helps him fight through his fears. By the skin of their teeth, Nathan and Zhang make the cut to compete in Cambridge.
Who comes under the tutelage of a math genius teacher?