Question: who was the us president when the united nations was formed
[{'answer': 'President Franklin D. Roosevelt', 'provenance': [{'wikipedia_id': '1157540', 'title': 'History of the United Nations', 'start_paragraph_id': 6, 'start_character': 68, 'end_paragraph_id': 6, 'end_character': 99, 'bleu_score': 1.0, 'section': 'Section::::Origins.:1942 "Declaration of United Nations".\n'}]}, {'provenance': [{'wikipedia_id': '1157540', 'title': 'History of the United Nations', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 612, 'bleu_score': 0.9450701851959151, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17928659696160693172}, 'section': 'Section::::Origins.:1942 "Declaration of United Nations".\n'}]}]