Question: who played the president in iron man 3
[{'answer': 'William Sadler', 'provenance': [{'wikipedia_id': '22144990', 'title': 'Iron Man 3', 'start_paragraph_id': 22, 'start_character': 151, 'end_paragraph_id': 22, 'end_character': 165, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'provenance': [{'wikipedia_id': '22144990', 'title': 'Iron Man 3', 'start_paragraph_id': 22, 'start_character': 0, 'end_paragraph_id': 22, 'end_character': 1268, 'bleu_score': 0.864528154064467, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2682126013931223348}, 'section': 'Section::::Cast.\n'}]}]