Introduction to the first floor: At the entrance to the first floor of the Red Building, there is a bust of Cai Yuanpei, the former president of Peking University. On December 26, 1916, Cai Yuanpei was appointed president of Peking University. He "followed the principle of freedom of thought and embraced inclusiveness and justice", which enabled Peking University to emancipate its thoughts and achieve academic prosperity. Peking University has been changing with each passing day since then.