Question: how many gates are there in nagarjuna sagar dam
[{'answer': '26', 'provenance': [{'wikipedia_id': '3467915', 'title': 'Nagarjuna Sagar Dam', 'start_paragraph_id': 1, 'start_character': 412, 'end_paragraph_id': 1, 'end_character': 414, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]