Question: who performed the first successful heart bypass operation in 1964
[{'answer': 'Vasilii Kolesov', 'provenance': [{'wikipedia_id': '195248', 'title': 'Coronary artery bypass surgery', 'start_paragraph_id': 97, 'start_character': 36, 'end_paragraph_id': 97, 'end_character': 51, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]