How many Catholic presidents have there been?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'INTERNAL', 'name_': 'Q19180675', 'id': 0, 'label': 'Small Brockhaus and Efron Encyclopedic Dictionary'}, {'type': 'INTERNAL', 'name_': 'Q602358', 'id': 1, 'label': 'Brockhaus and Efron Encyclopedic Dictionary'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q1841', 'id': 2, 'label': 'Catholicism'}, {'type': 'INTERNAL', 'name_': 'Q127', 'id': 3, 'label': 'Tuesday'}, {'type': 'INTERNAL', 'name_': 'Q23397', 'id': 4, 'label': 'lake'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q201', 'id': 5, 'label': '3'}], 'links': [{'name_': 'P1343', 'source': 2, 'target': 0, 'label': 'described by source'}, {'name_': 'P1343', 'source': 2, 'target': 1, 'label': 'described by source'}, {'name_': 'P140', 'source': 2, 'target': 2, 'label': 'religion or worldview'}, {'name_': 'P1343', 'source': 3, 'target': 1, 'label': 'described by source'}, {'name_': 'P138', 'source': 3, 'target': 5, 'label': 'named after'}, {'name_': 'P1343', 'source': 4, 'target': 0, 'label': 'described by source'}, {'name_': 'P1343', 'source': 4, 'target': 1, 'label': 'described by source'}, {'name_': 'P1963', 'source': 4, 'target': 5, 'label': 'properties for this type'}]}