Question: who wrote the song kahit maputi na ang buhok ko
[{'answer': 'Rey Valera', 'provenance': [{'wikipedia_id': '2307506', 'title': 'Rey Valera', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 10, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2307506', 'title': 'Rey Valera', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 494, 'bleu_score': 0.9371638731849671, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14235501041073310833}, 'section': 'Section::::Career.\n'}]}]