Question: who was the first us president to visit south korea
[{'answer': 'Dwight D. Eisenhower', 'provenance': [{'wikipedia_id': '51161081', 'title': 'United States presidential visits to East Asia', 'start_paragraph_id': 1, 'start_character': 139, 'end_paragraph_id': 1, 'end_character': 159, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]