Question: who was the leader of france when the us purchased the louisiana territory
[{'answer': 'Napoleon', 'provenance': [{'wikipedia_id': '17628', 'title': 'Louisiana Purchase', 'start_paragraph_id': 1, 'start_character': 306, 'end_paragraph_id': 1, 'end_character': 314, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '17628', 'title': 'Louisiana Purchase', 'start_paragraph_id': 24, 'start_character': 4, 'end_paragraph_id': 24, 'end_character': 615, 'bleu_score': 0.8629807497012281, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5869426167736457813}, 'section': 'Section::::Negotiation.\n'}]}]