Question: who are the living presidents of the united states
[{'answer': 'George H.W. Bush'}, {'answer': 'Jimmy Carter', 'provenance': [{'wikipedia_id': '8762618', 'title': 'Living presidents of the United States', 'start_paragraph_id': 1, 'start_character': 494, 'end_paragraph_id': 1, 'end_character': 506, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Donald Trump', 'provenance': [{'wikipedia_id': '8762618', 'title': 'Living presidents of the United States', 'start_paragraph_id': 1, 'start_character': 439, 'end_paragraph_id': 1, 'end_character': 451, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'George W. Bush', 'provenance': [{'wikipedia_id': '8762618', 'title': 'Living presidents of the United States', 'start_paragraph_id': 1, 'start_character': 522, 'end_paragraph_id': 1, 'end_character': 536, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Bill Clinton', 'provenance': [{'wikipedia_id': '8762618', 'title': 'Living presidents of the United States', 'start_paragraph_id': 1, 'start_character': 508, 'end_paragraph_id': 1, 'end_character': 520, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Barack Obama', 'provenance': [{'wikipedia_id': '8762618', 'title': 'Living presidents of the United States', 'start_paragraph_id': 1, 'start_character': 541, 'end_paragraph_id': 1, 'end_character': 553, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]