With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Streptococcus belongs to a set of things.
text_B: This is a list of people on stamps of Trinidad and Tobago and the individual islands .. stamps. Postage stamp. Trinidad and Tobago. Trinidad and Tobago. The list is complete through 1984 .
not_related.