How many named oceans are there in the world?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'INTERNAL', 'name_': 'Q51', 'id': 0, 'label': 'Antarctica'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q5107', 'id': 1, 'label': 'continent'}, {'type': 'INTERNAL', 'name_': 'Q97', 'id': 2, 'label': 'Atlantic Ocean'}, {'type': 'INTERNAL', 'name_': 'Q18', 'id': 3, 'label': 'South America'}, {'type': 'INTERNAL', 'name_': 'Q7354', 'id': 4, 'label': 'Southern Ocean'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q9430', 'id': 5, 'label': 'ocean'}], 'links': [{'name_': 'P31', 'source': 0, 'target': 1, 'label': 'instance of'}, {'name_': 'P31', 'source': 2, 'target': 5, 'label': 'instance of'}, {'name_': 'P31', 'source': 3, 'target': 1, 'label': 'instance of'}, {'name_': 'P206', 'source': 3, 'target': 2, 'label': 'located in or next to body of water'}, {'name_': 'P138', 'source': 4, 'target': 0, 'label': 'named after'}, {'name_': 'P31', 'source': 4, 'target': 5, 'label': 'instance of'}]}