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.

Premise: An enthusiastic young man runs with an exercise ball as he's being chased.
Hypothesis: A man and his friend is playing catch.
Update: The man throws the ball back to his friend.
strengthener

Premise: There are a lot of kids walking on train tracks surrounded by trees.
Hypothesis: THE grass was green
Update: The yellow grass was a result of the drought that had hit the area.
weakener

Premise: A dog walks through the water with an object in its mouth.
Hypothesis: A dog is walking through a stream.
Update: The dog carries its ball across the flooded street.

weakener