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: Two girls are standing behind another girl.
Hypothesis: Two girls are preparing to push a third girl.
Update: the third girl is on the top stair
weakener

Premise: Man in plaid shirt scaling rocks.
Hypothesis: A man is mountain climbing.
Update: The man has a small ice axe with him
strengthener

Premise: Several young African Americans giving an outdoor dance performance
Hypothesis: A group does tribal dancing at a festival.
Update: The people are wearing tribal masks.

strengthener