Definition: 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.

Positive Example 1 -
Input: Premise: Old man crafting something in his workshop.
Hypothesis: An old man is working.
Update: The man is serious and is surrounded by workers.
Output: strengthener

Positive Example 2 -
Input: Premise: Old man crafting something in his workshop.
Hypothesis: An old man is working.
Update: The man is wearing pajamas and is chuckling.
Output: weakener

Negative Example 1 -
Input: Premise: Old man crafting something in his workshop.
Hypothesis: An old man is working.
Update: The man is serious and is surrounded by workers.
Output: I dont know.

Negative Example 2 -
Input: Premise: Old man crafting something in his workshop.
Hypothesis: An old man is working.
Update: The man is wearing pajamas and is chuckling.
Output: strengthener,weakener.

Now complete the following example -
Input: Premise: A young girl wearing a light blue dress and a young boy wearing navy pants and a yellow shirt walk up the steps to the cockpit of an airplane sitting in the field of an aviation museum.
Hypothesis: A brother and sister are walking up the steps to an old silver airplane.
Update: The plane was used during World War II.
Output: 


Answer: strengthener