Question: who is the current us army chief of staff
[{'answer': 'General Mark A. Milley', 'provenance': [{'wikipedia_id': '485507', 'title': 'Chief of Staff of the United States Army', 'start_paragraph_id': 3, 'start_character': 42, 'end_paragraph_id': 3, 'end_character': 64, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '485507', 'title': 'Chief of Staff of the United States Army', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 64, 'bleu_score': 0.850733133512352, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7942968331964468976}, 'section': 'Section::::Abstract.'}]}]