Question: who performed the first open heart surgery in the world
[{'answer': 'Dr. John Carter Callaghan', 'provenance': [{'wikipedia_id': '804779', 'title': 'Cardiac surgery', 'start_paragraph_id': 10, 'start_character': 316, 'end_paragraph_id': 10, 'end_character': 341, 'bleu_score': 1.0, 'section': 'Section::::History.:20th century.\n'}]}, {'provenance': [{'wikipedia_id': '804779', 'title': 'Cardiac surgery', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 401, 'bleu_score': 0.9669306597086381, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10826076969865633560}, 'section': 'Section::::History.:20th century.\n'}]}]