Question: who won the men's 2009 australian open
[{'answer': 'Nadal', 'provenance': [{'wikipedia_id': '45213766', 'title': "2009 Australian Open – Men's singles final", 'start_paragraph_id': 1, 'start_character': 237, 'end_paragraph_id': 1, 'end_character': 242, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '45213766', 'title': "2009 Australian Open – Men's singles final", 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 411, 'bleu_score': 0.972407137066537, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12296359598797521099}, 'section': 'Section::::Abstract.'}]}]