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: A police officer is monitoring a by stander while guarding a building.
Hypothesis: The police officer is a man.
Update: The officer looks stern.
strengthener

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.
strengthener

Premise: A baby is sleeping with his hand on his face.
Hypothesis: A baby is sleeping in his crib.
Update: The sun shines through the car window into the baby's face.

weakener