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 surfer rides his surfboard at the start of a wave.
Hypothesis: There are several people surfing on big waves.
Update: The surfer worries that nobody will see him fall.
Example Output: weakener

Example Input: Premise: Four people wearing red, blue, white& black, walking up a white staircase overlooking a marina in an old city.
Hypothesis: The group of people are all part of a party.
Update: They are returning children on Halloween who wore matching costumes while trick or treating.
Example Output: weakener

Example Input: Premise: Two children wearing hats hang onto to bamboo trees.
Hypothesis: The kids are climbing trees.
Update: The children want to pick fruit at the top of the trees.
Example Output:
strengthener