Question: who was the president of russia in 1989
[{'answer': 'Mikhail Gorbachev', 'provenance': [{'wikipedia_id': '20979', 'title': 'Mikhail Gorbachev', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]