Question: who was serving as president of u.s. 1946
[{'answer': 'Harry S. Truman', 'provenance': [{'wikipedia_id': '3418303', 'title': 'Harry S. Truman', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]