Question: how many how to train your dragon books are there
[{'answer': 'twelve', 'provenance': [{'wikipedia_id': '5829721', 'title': 'How to Train Your Dragon', 'start_paragraph_id': 1, 'start_character': 40, 'end_paragraph_id': 1, 'end_character': 46, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '5829721', 'title': 'How to Train Your Dragon', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 534, 'bleu_score': 0.980097014099621, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6631097986623624628}, 'section': 'Section::::Abstract.'}]}]