Question: how many episodes of game of thrones have aired in season 7
[{'answer': 'seven', 'provenance': [{'wikipedia_id': '31120069', 'title': 'List of Game of Thrones episodes', 'start_paragraph_id': 2, 'start_character': 443, 'end_paragraph_id': 2, 'end_character': 448, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]