With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Streptococcus has a spherical shape and it is studied in the field of biology.
text_B: Convoy HG 73 was a trade convoy of merchant ships during the second World War .. convoy. convoy. second World War. second World War. It was the 73rd of the numbered HG convoys Homeward bound to the British Isles from Gibraltar .. HG convoys. Gibraltar convoys of World War II#HG convoys. British Isles. British Isles. The convoy departed Gibraltar on 17 September 1941 and was found on 18 September by a Focke-Wulf Fw 200 Condor of Kampfgeschwader 40 -LRB- KG 40 -RRB- .. convoy. convoy. Focke-Wulf Fw 200. Focke-Wulf Fw 200. The 25-ship convoy was attacked by five U-boats of 1st and 2nd U-boat Flotillas , operating out of Brest and Lorient , respectively .. U-boats. U-Boat. convoy. convoy. U-boat. U-boat. 1st. 1st U-boat Flotilla. Brest. Brest, France. Lorient. Lorient. They were initially assisted by Italian submarines Luigi Torelli , Morosini and Leonardo Da Vinci , that were en route to the Mediterranean .. Italian submarines. Italian submarines of World War II. Nine ships were sunk from the convoy before the submarines exhausted their torpedo inventory on 28 September .. convoy. convoy. Surviving ships reached Liverpool on 1 October .. Liverpool. Liverpool
not_related.