Where does the rail route, which ends at the Moskovsky station, begins?
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/routeEnd> <http://dbpedia.org/resource/Moskovsky_railway_station_(Saint_Petersburg)> . ?x <http://dbpedia.org/ontology/routeStart> ?uri  . }
Moskovsky_railway_station_(Saint_Petersburg)