With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Black Sabbath are often called pioneers of a genre of music.
text_B: 53rd parallel may refer to  :. 53rd parallel north , a circle of latitude in the Northern Hemisphere. 53rd parallel north. 53rd parallel north. 53rd parallel south , a circle of latitude in the Southern Hemisphere. 53rd parallel south. 53rd parallel south
not_related.