Question: how many huey helicopters were shot down in vietnam
[{'answer': '69', 'provenance': [{'wikipedia_id': '686151', 'title': 'List of aircraft losses of the Vietnam War', 'start_paragraph_id': 22, 'start_character': 103, 'end_paragraph_id': 22, 'end_character': 105, 'bleu_score': 1.0, 'section': 'Section::::United States aircraft.:United States Air Force.:USAF fixed-wing.\n'}]}]