How many {student of} are to/by {Charles Gounod} ?
How many students are taught by Charles Gounod?
SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1066 wd:Q180278 }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1066> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q180278 .
} 

Charles Gounod has how many students?