Question: how many episodes of doctor foster are there
[{'answer': '7', 'provenance': [{'wikipedia_id': '42101143', 'title': 'Doctor Foster (TV series)', 'start_paragraph_id': 2, 'start_character': 525, 'end_paragraph_id': 2, 'end_character': 526, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]