Question: Which frequent flyer program has the most airlines?
SPARQL query:
PREFIX onto: <http://dbpedia.org/ontology/> 
PREFIX prop: <http://dbpedia.org/property/> 
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> 
PREFIX yago: <http://dbpedia.org/class/yago/> 	
SELECT ?uri 
WHERE { 
         ?airline rdf:type onto:Airline. 
         ?airline prop:frequentFlyer ?uri.
         ?uri rdf:type yago:FrequentFlyerPrograms.

}
ORDER BY DESC(COUNT(DISTINCT ?airline))
OFFSET 0 LIMIT 1