Question: what was the longest shootout in nhl history
[{'answer': '20 rounds', 'provenance': [{'wikipedia_id': '568092', 'title': 'Overtime (ice hockey)', 'start_paragraph_id': 23, 'start_character': 488, 'end_paragraph_id': 23, 'end_character': 497, 'bleu_score': 1.0, 'section': 'Section::::Shootout.:North American shootouts.\n'}]}, {'provenance': [{'wikipedia_id': '568092', 'title': 'Overtime (ice hockey)', 'start_paragraph_id': 23, 'start_character': 0, 'end_paragraph_id': 23, 'end_character': 618, 'bleu_score': 0.9173445714175771, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7090921092492710073}, 'section': 'Section::::Shootout.:North American shootouts.\n'}]}]