Question: who sings the song when i was your man
[{'answer': 'Bruno Mars', 'provenance': [{'wikipedia_id': '37825120', 'title': 'When I Was Your Man', 'start_paragraph_id': 1, 'start_character': 66, 'end_paragraph_id': 1, 'end_character': 76, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '37825120', 'title': 'When I Was Your Man', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 413, 'bleu_score': 0.7769481756417881, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11669055543476445680}, 'section': 'Section::::Abstract.'}]}]