How many countries are in Central America?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q800', 'id': 0, 'label': 'Costa Rica'}, {'type': 'INTERNAL', 'name_': 'Q190025', 'id': 1, 'label': 'Federal Republic of Central America'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q27611', 'id': 2, 'label': 'Central America'}], 'links': [{'name_': 'P150', 'source': 1, 'target': 0, 'label': 'contains the administrative territorial entity'}, {'name_': 'P706', 'source': 1, 'target': 2, 'label': 'located in/on physical feature'}]}