With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Rihanna is one of the best-selling musicians of all time.
text_B: The was a class of amphibious assault ships of the Imperial Japanese Navy -LRB- IJN -RRB- , serving during and after World War II .. Imperial Japanese Navy. Imperial Japanese Navy. World War II. World War II. The IJN also called them .
not_related.