With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Nirvana and Soundgarden were contemporaries in Seattle.
text_B: Pterolophia gigas is a species of beetle in the family Cerambycidae .. Cerambycidae. Cerambycidae. Pterolophia. Pterolophia. beetle. beetle. It was described by Pic in 1937 .
not_related.