Question: who is number 20 for the dallas cowboys
[{'answer': 'Sherman Williams', 'provenance': [{'wikipedia_id': '10150801', 'title': 'Sherman Williams (American football)', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]