With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Divergent came out in disc format in 2014.
text_B: The Lost City of the Kalahari is a historical mystery of exploration and archaeology dating to the end of the 19th century .. The history reports the existence of a ruined city found in the Kalahari Desert in southern Africa .. Kalahari Desert. Kalahari Desert
not_related.