Question: who is the longest reigning wwe united states champion
[{'answer': 'Lex Luger', 'provenance': [{'wikipedia_id': '985725', 'title': 'List of WWE United States Champions', 'start_paragraph_id': 4, 'start_character': 190, 'end_paragraph_id': 4, 'end_character': 199, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '985725', 'title': 'List of WWE United States Champions', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 538, 'bleu_score': 0.9385289250847371, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6027677077041053972}, 'section': 'Section::::Abstract.'}]}]