Which book of the Hobbit series is the longest?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'INTERNAL', 'name_': 'Q81738', 'id': 0, 'label': "Tolkien's legendarium"}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q74287', 'id': 1, 'label': 'The Hobbit'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q208002', 'id': 2, 'label': 'The Fellowship of the Ring'}], 'links': [{'name_': 'P1445', 'source': 0, 'target': 1, 'label': 'fictional universe described in'}, {'name_': 'P1445', 'source': 0, 'target': 2, 'label': 'fictional universe described in'}]}