Question: who was the first ruler of the mali empire
[{'answer': 'Sundiata Keita', 'provenance': [{'wikipedia_id': '182049', 'title': 'Mali Empire', 'start_paragraph_id': 1, 'start_character': 204, 'end_paragraph_id': 1, 'end_character': 218, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '182049', 'title': 'Mali Empire', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 820, 'bleu_score': 0.922450655494614, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17579625917317270613}, 'section': 'Section::::Abstract.'}]}]