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.

Q: Premise: A man is performing acrobatics over a group of people kneeling on the ground.
Hypothesis: The acrobat is doing a hard trick.
Update: The acrobat is concentrating very intently.

A: strengthener
****
Q: Premise: A boy in a black shirt punches a yellow punching bag while a boy in a blue sweatshirt holds the bag.
Hypothesis: Two boys take turns using a punching bag.
Update: They are both training.

A: strengthener
****
Q: Premise: There is a man in a suit speaking in a microphone in front of a screen.
Hypothesis: The man is an actor talking about the movie at a premiere.
Update: On the screen is a paused frame of the man in a movie.

A:
strengthener
****