With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Cara Delevingne was involved with a thriller film directed by Mathew Cullen and written by Roberta Hanley called London Fields.
text_B: On 25 January 2014 , Chang Ter-cheng attempted to drive a 35-tonne truck through the main doors of the Presidential Office Building , Taiwan .
not_related.