With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Vacation stars three comedian directors.
text_B: The Equatorial Sextant , also known as Altitude Instrument , was first invented and made by William Austin Burt .. William Austin Burt. William Austin Burt. He patented it November 4 , 1856 , in the United States as patent No. 16,002 , which was followed by patents in England , France and Belgium .. The purpose of this type of sextant was to get an accurate position of a ship at sea .. Burt applied the principles of his earlier Solar Compass invention to navigation .. Solar Compass. Solar Compass
not_related.