With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The gray wolf is a species of Canis.
text_B: The Valea Baciului River is a tributary of the Valea Mare River in Romania .. Romania. Romania. Valea Mare. Valea Mare River ( Barzava ). tributary. tributary. Valea Mare River. Valea Mare River ( Barzava )
not_related.