With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Robert Richardson has only ever collaborated with women.
text_B: Anthidium montanum is a species of bee in the family Megachilidae , the leaf-cutter , carder , or mason bees .. bee. bee. family. Family ( biology ). Megachilidae. Megachilidae
not_related.