A teacher is dismayed that so many students are skipping her Zoom lectures. Her next lecture is an important one, and she wants everyone to attend. To encourage this, she considers failing any student who skips the next session. Unfortunately, by university rules, she can fail only one student. The students all know this and plan to stay away on the argument that the probability of any one of them failing as a result is low. Though the students are willing to accept a low probability of failing, none is willing to skip class if it means failing for sure. What policy can the teacher announce that would persuade all of her students to attend the next session?