With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Stagira is an ancient Greek city.
text_B: Sindernbach is a river of North Rhine-Westphalia , Germany , which is 3.58 kilometers in length .. Germany. Germany. North Rhine-Westphalia. North Rhine-Westphalia. It has its source on the east of the mountain Lahnkopf in the Rothaar Mountains in a height of 570 meters , and it flows into the river Sieg in the village of Nenkersdorf in a height of 365 meters above sea level .. Sieg. Sieg
not_related.