An elite Chinese aeronautical university is forcing students who want to use the Wi-fi in the canteen to solve a fiendishly difficult maths equation first, according to the local broadcaster. Students dining at the Xinyuan Ethnic Restaurant in Nanjing University of Aeronautics and Astronautics had to solve a complex calculus equation and use the answer as the password. The university confirmed in an official Weibo post on Thursday that it had put up the sign in its canteen and shared one social media user’s calculation of the solution – which turned out to be the first digits of Pi. The post continued: “Don’t ask us why we did it when we can fly.” The university, nicknamed “Nanhang” in Chinese, mainly offers courses in science and engineering. It specialises in aeronautics, space flight and civil aviation. Another poster in the school’s catering services centre reminded students: “All of us at Nanhang ought to be geeks, right? If you can’t solve a calculus equation then go and study, don’t use our Wi-fi.” Commenters online were not so impressed. Rat in hotpot shocks pregnant woman, shuts down restaurant “When one person solves it, the entire school will know what it is,” read one top-rated comment on Weibo. A canteen manager at the school told Nanjing news site Longhoo.net that the catering staff wanted to share a small joke with the students after the canteens were refurbished over the summer. “We didn’t know that the reaction would be as strong as this,” Chen Jie was quoted as saying. Trump and the trade war won’t stop Chinese studying in America Based in the eastern province of Jiangsu, the institution has 13 themed student canteens, including the ethnic restaurant that specialises in foods from China’s minority groups and one that mimics the design of an aeroplane cabin. Other canteens at the university also like to put their students to the test. A sign at the Xinyuan Library Restaurant asked students to name the notes in a line of music to access the Wi-fi password there, according to a photo posted by Nanhang’s official Weibo account on Thursday. The notes, CCGGAAG, made up the opening bars of Twinkle, Twinkle Little Star .