Question: what country did the united states buy the gadsden purchase from
[{'answer': 'James Gadsden', 'provenance': [{'wikipedia_id': '143163', 'title': 'Gadsden Purchase', 'start_paragraph_id': 2, 'start_character': 52, 'end_paragraph_id': 2, 'end_character': 65, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]