Question: who starred in the movie dances with wolves
[{'answer': 'Kevin Costner', 'provenance': [{'wikipedia_id': '129585', 'title': 'Dances with Wolves', 'start_paragraph_id': 1, 'start_character': 91, 'end_paragraph_id': 1, 'end_character': 104, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Mary McDonnell', 'provenance': [{'wikipedia_id': '129585', 'title': 'Dances with Wolves', 'start_paragraph_id': 18, 'start_character': 12, 'end_paragraph_id': 18, 'end_character': 26, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'answer': 'Graham Greene', 'provenance': [{'wikipedia_id': '129585', 'title': 'Dances with Wolves', 'start_paragraph_id': 19, 'start_character': 12, 'end_paragraph_id': 19, 'end_character': 25, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'answer': 'Rodney Grant'}]