With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Rick and Morty was renewed for a fourth season in 2014.
text_B: A constitutional referendum was held in Panama on 15 December 1940 .. Panama. Panama. Voters were asked whether the new constitution should be enacted .. new constitution. Constitution of Panama. A reported 98.7 % voted in favour .
not_related.