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.

Input: Consider Input: Premise: A flying machine with a yellow sail is landing with industrial buildings in the background.
Hypothesis: The machine is not gas-operated.
Update: The machine has a battery.

Output: strengthener


Input: Consider Input: Premise: Middle-age students sitting in rows of tables listening to a teacher sitting in front of room behind desk.
Hypothesis: The teacher is teaching the students about classic literature.
Update: Math problems are written on the chalkboard.

Output: weakener


Input: Consider Input: Premise: A woman and a man sitting outside.
Hypothesis: A married couple sit outside.
Update: They talk together about their mates.


Output: weakener