Question: who won the men's single title of australia open on 1 february 2015
[{'answer': 'Djokovic', 'provenance': [{'wikipedia_id': '44445163', 'title': "2015 Australian Open – Men's Singles", 'start_paragraph_id': 1, 'start_character': 6, 'end_paragraph_id': 1, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Novak Djokovic', 'provenance': [{'wikipedia_id': '44445163', 'title': "2015 Australian Open – Men's Singles", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '44445163', 'title': "2015 Australian Open – Men's Singles", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 309, 'bleu_score': 0.5862321292860511, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14765574147294874970}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '44445163', 'title': "2015 Australian Open  Men's Singles", 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ["Novak Djokovic defeated Andy Murray 76, 67, 63, 60 in the final to win the Men's Singles tennis title at the 2015 Australian Open.", "Novak Djokovic defeated Andy Murray 76, 67, 63, 60 in the final to win the Men's Singles tennis title at the 2015 Australian Open", "Novak Djokovic defeated Andy Murray 76, 67, 63, 60 in the final to win the Men's Singles tennis title at the 2015 Australian Open. The defeat saw Murray lose the Australian Open final for the fourth time in his career, becoming the first man in the Open Era to achieve four runner-up finishes in Melbourne."]}}]}]