How many NFL teams did Len Dawson play on?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q191477', 'id': 0, 'label': 'Pittsburgh Steelers'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q1215884', 'id': 1, 'label': 'National Football League'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q726229', 'id': 2, 'label': 'Len Dawson'}], 'links': [{'name_': 'P118', 'source': 0, 'target': 1, 'label': 'league'}, {'name_': 'P54', 'source': 2, 'target': 0, 'label': 'member of sports team'}]}