Question: how many episodes are in the last season of vampire diaries
[{'answer': '16', 'provenance': [{'wikipedia_id': '50959719', 'title': 'The Vampire Diaries (season 8)', 'start_paragraph_id': 1, 'start_character': 113, 'end_paragraph_id': 1, 'end_character': 115, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]