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: A black and brown dog is running out of the surf.
Hypothesis: A dog is swimming excitedly.
Update: The dog swims with great enthusiasm out of the water.
Example Output: strengthener

Example Input: Premise: A boat is illuminated at night.
Hypothesis: A boat is using the lights to see at night.
Update: There is a tug boat pulling up to the boat with men shining lights in to the boat.
Example Output: weakener

Example Input: Premise: Pilot getting off his plane with and an engineer looking at the steps.
Hypothesis: A pilot lets an engineer check the steps of the plane
Update: The pilot is friends with the engineer.
Example Output:
strengthener