Question: who's the head coach of the buffalo bills
[{'answer': 'Sean McDermott', 'provenance': [{'wikipedia_id': '17216640', 'title': 'List of Buffalo Bills head coaches', 'start_paragraph_id': 4, 'start_character': 395, 'end_paragraph_id': 4, 'end_character': 409, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '17216640', 'title': 'List of Buffalo Bills head coaches', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 1789, 'bleu_score': 0.933895634945727, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13103222731889420200}, 'section': 'Section::::Abstract.'}]}]