During the Three Kingdoms period, Ma Teng, the secretariat of Xiliang, gave Cao Cao a box of crisp cakes, on which Cao Cao wrote the word "one crisp". Yang Xiu understood "one-in-one crispness" as one bite for each person, because ancient characters were vertical. At that time, Cao Cao just let his ministers guess (another explanation is that Cao Cao was afraid that Marten would poison his breasts, so he mystified his men to try poison), and only Yang Xiu knew the meaning. However, Yang Xiu's arrogance was suspected by Cao Cao, which also laid the groundwork for Yang Xiuzhi's death.