With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Conan O'Brien is a businessman.
text_B: Kasteel van Arenberg is a chateau in Heverlee close to Leuven in Belgium .. chateau. chateau. Heverlee. Heverlee. Leuven. Leuven. Belgium. Belgium. It is surrounded by a park .
not_related.