With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Twitter's headquarters are in San Francisco.
text_B: The Ateliers et Chantiers de France -LRB- ACF , Workshops and Shipyards of France -RRB- was a major shipyard that was established in Dunkirk , France in 1898 .. Dunkirk. Dunkirk. The shipyard boomed in the period before World War I -LRB- 1914 -- 18 -RRB- , but struggled in the inter-war period .. World War I. World War I. It was badly damaged during World War II -LRB- 1939 -- 45 -RRB- .. World War II. World War II. In the first thirty years after the war the shipyard again experienced a boom and employed up to 3,000 workers making oil tankers , and then liquid natural gas tankers .. Demand dropped off in the 1970s and 1980s .. In 1972 the shipyard became Chantiers de France-Dunkerque , and in 1983 merged with others yards to become part of Chantiers du Nord et de la Mediterranee , or Normed .. The shipyard closed in 1987 .
not_related.