Question: who was the only us president that was never elected either president or vice president
[{'answer': 'Gerald Rudolph Ford Jr.', 'provenance': [{'wikipedia_id': '5030380', 'title': 'Gerald Ford', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 23, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '5030380', 'title': 'Gerald Ford', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 459, 'bleu_score': 0.75340069689829, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14575727679792202802}, 'section': 'Section::::Abstract.'}]}]