Question: In how many countries does the Zurich Affoltern am Albis Zug line go?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:line <http://dbpedia.org/resource/Zürich–Affoltern_am_Albis–Zug_railway_line> . ?x onto:country ?uri  . ?uri rdf:type onto:Country}