Question: who sang 666 the number of the beast
[{'answer': 'Iron Maiden', 'provenance': [{'wikipedia_id': '4893894', 'title': 'The Number of the Beast (song)', 'start_paragraph_id': 1, 'start_character': 68, 'end_paragraph_id': 1, 'end_character': 79, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4893894', 'title': 'The Number of the Beast (song)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 371, 'bleu_score': 0.952004915197278, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16449685067518167623}, 'section': 'Section::::Abstract.'}]}]