Which of the four surviving sons of Louis VIII of France did not have any children?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q165284', 'id': 0, 'label': 'Louis VIII of France'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q343969', 'id': 1, 'label': 'Alphonse, Count of Poitiers'}], 'links': [{'name_': 'P40', 'source': 0, 'target': 1, 'label': 'child'}]}