One sleepy afternoon, in solid geometry class, Gu Ziyi hung up the blackboard for the first time in his life, and couldn't write a single word on the podium for a long time. At this time, Yan Xuwu, who was sitting across the aisle from Gu Ziyi, was caught reading a magazine by the math teacher. "You know what I'm talking about? Are you still here reading a magazine!" "Yes." "Then you go up and do it!" "You go down." Yan Xuwu approached Gu Ziyi, who was lowering his head with a blush on his face, and whispered. It only took less than two minutes to finish solving the problem. When he was about to return to his seat, he said, "It's done, not bad. But when it comes to reading magazines, you stand at the door and reflect on it!" After finishing speaking, Old Hao walked up to the podium and continued to lecture. Yan Xuwu: ... After his chaos, Gu Ziyi felt that hanging the blackboard was not so embarrassing anymore. Later, the two became roommates. Gu Ziyi found that Yan Xuwu was very vigilant and would never be caught reading magazines. He only thought that he might have been unlucky that time. Many years later, "I deliberately rescued you back then, didn't you see that?"