How many nations' volleyball players have played for the Russian women volleyball team?
SELECT DISTINCT COUNT(?uri) WHERE { ?x <http://dbpedia.org/property/nationalteam> <http://dbpedia.org/resource/Russia_women's_national_volleyball_team> . ?x <http://dbpedia.org/property/placeOfBirth> ?uri  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Country>}
Russia_women's_national_volleyball_team