With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Mike Tyson was a professional heavyweight boxer.
text_B: Dioon califanoi is a species of cycad that is native to Oaxaca , Mexico .. species. species. cycad. cycad. Mexico. Mexico. thumb  |  left  |  250px  |  With cones in a greenhouse at Paloma Gardens , New Zealand. thumb. image :Flickr - brewbooks - Cycads in the greenhouse - Paloma gardens ( 1 ).jpg
not_related.