How many books are in the Shadow and Bone series?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q7460625', 'id': 0, 'label': 'Shadow and Bone'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q85800564', 'id': 1, 'label': 'Shadow and Bone'}], 'links': [{'name_': 'P144', 'source': 1, 'target': 0, 'label': 'based on'}]}