For how many cities's teams did David Bowens play?
SELECT DISTINCT COUNT(?uri) WHERE { <http://dbpedia.org/resource/David_Bowens> <http://dbpedia.org/ontology/formerTeam> ?x . ?x <http://dbpedia.org/ontology/locationCity> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/SportsTeam>}
David_Bowens