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, that is, it makes you much less likely to believe the hypothesis is true. A strengthener is a statement that strengthens the hypothesis, that is, it makes you much more likely to believe the hypothesis is true. Your task is to answer with 'strengthener' or 'weakener' if the update strengthens or weakens the hypothesis, respectively.
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Question: Premise: A gray dog is in grass.
Hypothesis: A dog is sitting in the grass
Update: The dog's tail cannot be seen because the dog's bottom is on the ground.

Answer: strengthener


Question: Premise: A man in a blue shirt is pushing another man in a white shirt during football practice.
Hypothesis: The offensive man is blocking the defense.
Update: The offensive man is blocking the exit from the football field.

Answer: weakener


Question: Premise: A large crowd of people are walking down the street.
Hypothesis: A group is walking to a festival.
Update: It's raining and thundering.

Answer:
weakener