Question: how many episodes of stranger things season 2 are there
[{'answer': '9', 'provenance': [{'wikipedia_id': '46301800', 'title': 'Stranger Things', 'start_paragraph_id': 2, 'start_character': 60, 'end_paragraph_id': 2, 'end_character': 61, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]