Question: who was the shortest president of the united states
[{'answer': 'James Madison', 'provenance': [{'wikipedia_id': '748935', 'title': 'Heights of presidents and presidential candidates of the United States', 'start_paragraph_id': 2, 'start_character': 75, 'end_paragraph_id': 2, 'end_character': 88, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]