How many {rector} are for {Charles University in Prague} ?
Charles University in Prgue has how may reactors?
How many reactors are there for the {Charles University in Prague} ?
SELECT ( COUNT ( ?v ) AS ?t ) { resource:Charles_University property:rector ?v }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q31519> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1075> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q31519 wdt:P1075 ?obj }
1