Question: who was the last 5 presidents of the united states
[{'answer': 'Donald Trump', 'provenance': [{'wikipedia_id': '19908980', 'title': 'List of Presidents of the United States', 'start_paragraph_id': 2, 'start_character': 361, 'end_paragraph_id': 2, 'end_character': 373, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Barack Obama'}, {'answer': 'George W. Bush'}, {'answer': 'Bill Clinton'}, {'answer': 'George H.W. Bush'}]