Question: who has the most wins as a head coach in the nfl
[{'answer': 'Don Shula', 'provenance': [{'wikipedia_id': '41018355', 'title': 'List of National Football League head coaches with 50 wins', 'start_paragraph_id': 2, 'start_character': 18, 'end_paragraph_id': 2, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]