With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Leonardo da Vinci is completely unaffiliated with Ludovico il Moro.
text_B: A list of the films produced in Mexico in 1978 -LRB- see also 1978 in film -RRB-  :. Mexico. Mexico. 1978 in film. 1978 in film
not_related.