With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Stuart Sutcliffe was the original bass player of the Beatles.
text_B: The Munchenstein rail disaster on 14 June 1891 was historically the worst railway accident ever to affect Switzerland .. Switzerland. Switzerland. Munchenstein. Munchenstein. A crowded passenger train fell through a girder bridge , killing over seventy people and injuring many more .. girder bridge. girder bridge. The accident occurred on the railway line between Basel and Delemont , near the Bruckgut just below the village centre of Munchenstein , as the train was traversing the bridge across the river Birs .. Basel. Basel. Delemont. Delemont. Bruckgut. Bruckgut ( Munchenstein ). Munchenstein. Munchenstein. Birs. Birs
not_related.