Question: who has won the most nhl mvp awards
[{'answer': 'Wayne Gretzky', 'provenance': [{'wikipedia_id': '113663', 'title': 'Hart Memorial Trophy', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '113663', 'title': 'Hart Memorial Trophy', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 506, 'bleu_score': 0.976327165973018, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8063288422964922286}, 'section': 'Section::::History.\n'}]}]