With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Purple Haze was written by Jimi Hendrix.
text_B: `` Social Psychology '' is the fourth episode of the first season of the American comedy television series Community .. Community. Community ( TV series ). It aired in the United States on NBC on October 8 , 2009 .. NBC. NBC
not_related.