Question: when did the beatles become popular in britain
[{'answer': '1963', 'provenance': [{'wikipedia_id': '29812', 'title': 'The Beatles', 'start_paragraph_id': 17, 'start_character': 84, 'end_paragraph_id': 17, 'end_character': 88, 'bleu_score': 1.0, 'section': 'Section::::History.:1957–1962: Formation, Hamburg, and UK popularity.\n'}]}]