Question: what city is russia’s largest metropolitan area as measured by population
[{'answer': 'Moscow', 'provenance': [{'wikipedia_id': '24320051', 'title': 'Saint Petersburg', 'start_paragraph_id': 1, 'start_character': 58, 'end_paragraph_id': 1, 'end_character': 64, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '24320051', 'title': 'Saint Petersburg', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 283, 'bleu_score': 0.772953774837923, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1810875290371654095}, 'section': 'Section::::Abstract.'}]}]