We are engineering students, and most of the exams have draft paper, and the draft paper is standard, so it is not enough to bring other papers. The monitor deliberately scribbled on the first draft paper every exam, and then asked the invigilator for a second one. The second one was carefully preserved, and the key points of the next exam were copied on it. While we were still secretly turning over the cheat sheets, the monitor had the audacity to take out the "draft paper" prepared in advance and start writing! With this bold and cautious skill, the monitor got more than 80 points in every exam, with one exception. That's an ideological exam, the monitor thought. This kind of liberal arts exam, combined with his technique, is more like a dragon entering the sea, a tiger entering the abyss, a donkey getting water, and a mouse adding wings! Then write and write on the draft paper several days in advance. Moreover, in order to make the draft paper more realistic, people have realized that they have mixed all kinds of problems and made criss-crossing cheat sheets. In the middle of the exam, the monitor turned over the draft paper and the invigilator came over. "What are you?" "Isn't this draft paper?" "There is no draft paper for this exam." "Huh?" "Ah," the two men pondered for a long time. The invigilator reluctantly took the monitor's draft paper. The monitor was glad that the invigilator confiscated his paper because he had copied enough.