Question: how many electoral districts are there in the us
[{'answer': '435', 'provenance': [{'wikipedia_id': '19265315', 'title': 'Lists of electoral districts by nation', 'start_paragraph_id': 130, 'start_character': 157, 'end_paragraph_id': 130, 'end_character': 160, 'bleu_score': 1.0, 'section': 'Section::::United States.\n'}]}, {'provenance': [{'wikipedia_id': '19265315', 'title': 'Lists of electoral districts by nation', 'start_paragraph_id': 130, 'start_character': 0, 'end_paragraph_id': 130, 'end_character': 681, 'bleu_score': 0.9810405040225261, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8597245914572723532}, 'section': 'Section::::United States.\n'}]}]