With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: South Korea is a developed country in East Asia.
text_B: The Short S. 45 -- also known as the Short T. 5 after its naval serial number -- was a training biplane built for Britain 's Royal Navy by Short Brothers in 1912 .. Royal Navy. Royal Navy. Short Brothers. Short Brothers. It was the forerunner of another three identical aircraft -LRB- designated S. 48 , S. 49 , and S. 50 by Shorts -RRB- delivered to the Royal Navy and Royal Flying Corps during 1912 and 1913 .. Royal Navy. Royal Navy. The Royal Naval Air Service was still operating the type when World War I broke out in 1914 .. Royal Naval Air Service. Royal Naval Air Service
not_related.