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 young african boy skipping rocks.
Hypothesis: There is a rock currently skipping down a pond.
Update: There are several expanding sets of rings on the surface of the pool.

Answer: strengthener


Question: Premise: Several people standing in the street.
Hypothesis: people were waiting for the light to change so they could cross
Update: The police officer was holding them up with his hand.

Answer: strengthener


Question: Premise: A group of adolescents dressed in uniforms are walking down the street.
Hypothesis: The teenagers are on their way to school.
Update: They dressed up as firemen for Halloween.

Answer:
weakener