With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The Communist Party of the Soviet Union was the founding party of the Union of Soviet Socialist Republics.
text_B: The centered polygonal numbers are a class of series of figurate numbers , each formed by a central dot , surrounded by polygonal layers with a constant number of sides .. Each side of a polygonal layer contains one dot more than a side in the previous layer , so starting from the second polygonal layer each layer of a centered k-gonal number contains k more points than the previous layer .
not_related.