Question: who has the most billboard number 1 hits
[{'answer': 'The Beatles', 'provenance': [{'wikipedia_id': '2654171', 'title': 'List of Billboard Hot 100 chart achievements and milestones', 'start_paragraph_id': 245, 'start_character': 2, 'end_paragraph_id': 245, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::Artist achievements.:Self-replacement at number one.\n'}]}]