Question: name of the city that the first russian state centered around
[{'answer': 'Kiev', 'provenance': [{'wikipedia_id': '21486360', 'title': "Kievan Rus'", 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 4, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '21486360', 'title': "Kievan Rus'", 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 803, 'bleu_score': 0.9043360987684431, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8238319441131892913}, 'section': 'Section::::Abstract.'}]}]