In this task, you are given a premise, a hypothesis, and an update. The premise sentence describes a real-world situation and is always assumed to be true. The hypothesis sentence describes an assumption or inference that you might make about that situation having read the premise. The update provides additional information about the situation that might weaken or strengthen the hypothesis. A weakener is a statement that weakens the hypothesis. It makes you much less likely to believe the hypothesis is true. A strengthener is a statement that strengthens the hypothesis. It makes you much more likely to believe the hypothesis is true. Your task is to output 'strengthener' or 'weakener' if the update strengths or weakens the hypothesis, respectively.
Example: Premise: PersonX seems interested
Hypothesis: PersonX then good activity
Update: PersonX was a good student
Example solution: strengthener
Example explanation: If PersonX was a good student, it is more likely that PersonX would do good activities.

Problem: Premise: PersonX buys an air purifier
Hypothesis: Before, PersonX needed to go to a suitable store
Update: PersonX gets regular deliveries from an online store.
Solution: weakener