With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Southport is the host of the Southport Airshow.
text_B: The 2010 -- 11 season was Portogruaro 's 20th season of football and it is the first season in the Serie B , Italian second division .. Portogruaro. Calcio Portogruaro Summaga. Serie B. Serie B
not_related.