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.

Example Input: Premise: An icy, snowy city street with a bike resting against a pole.
Hypothesis: The bike is covered in snow.
Update: There are fresh tire track behind the bike.
Example Output: weakener

Example Input: Premise: Two men playing stringed instruments.
Hypothesis: Two guys are preparing for a concert.
Update: They sit in front of their cases in a local park.
Example Output: weakener

Example Input: Premise: Two young boys are running through a grassy area.
Hypothesis: Brothers are running through the park on their way home.
Update: There are swings and slides near the children.
Example Output:
strengthener