András, a sports glider winner with a "golden crown", is a first year student at the polytechnic and a pilot in the University Aeroclub. Accompanied by his flight colleagues, he leaves in a hurry from the airfield to college to attend the colloquium. Only Dr. Tóth stands at the door of the exam room, but entering, he finds with surprise that the "examiner" is in fact his young mathematics teacher. At the first exam ticket, he doesn't have much to do because he didn't learn. Benevolently, the attractive nurse offers him the second ticket, but he doesn't know much about it. So the student did not learn, so the exam failed. Simple: always 2x2 = 4! Yes, but András wants to prove that this is not always the case, that there are other factors that, if taken into account, can lead to another result. Of course, but not in math,