With no explanation, label text_A→text_B with either "strengthener" or "weakener".
text_A: In the autumn, two men run in opposite directions down a path that leads over a bridge and through the woods, while two others walking a dog are stopped on the bridge. Two people with dogs are stopped on a bridge because they're tired.
text_B: The dog walkers nodded to each other as they passed by.
weakener.