Question: how many us supreme court justices are there
[{'answer': '9', 'provenance': [{'wikipedia_id': '31737', 'title': 'Supreme Court of the United States', 'start_paragraph_id': 1, 'start_character': 183, 'end_paragraph_id': 1, 'end_character': 184, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]