With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Las Vegas is a suburb.
text_B: Pavetta holstii is a species of plant in the Rubiaceae family .. Rubiaceae. Rubiaceae. Pavetta. Pavetta. plant. plant. It is endemic to Tanzania .. endemic. Endemism. Tanzania. Tanzania
not_related.