In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.
Example: This list contains the top 25 accounts with the most followers on the social photo-sharing platform Instagram. As of May 2018, the most followed user is Instagram's own account, with over 235 million followers. Selena Gomez is the most followed individual, with over 137 million followers. Ten accounts have exceeded 100 million followers on the site.
Example solution: who has the maximum number of followers on instagram
Example explanation: The answer is talking about the Instagram accounts that have the most followers. The question asking about the maximum number of followers. So this is a good example.

Problem: Professor X is the founder of Xavier's School for Gifted Youngsters at a location commonly called the X-Mansion, which recruits mutants from around the world. Located in Westchester County, New York, the X-Mansion is the home and training site of the X-Men. The founding five members of the X-Men who appear in The X-Men #1 (September 1963) are Angel (Archangel), Beast, Cyclops, Iceman, and Marvel Girl (Jean Grey); Professor X and Magneto also made their first appearances in The X-Men #1. Since then, dozens of mutants from various countries and diverse backgrounds have held membership as X-Men.
Solution: who joined the x-men in x-men #1 from 1963