How many {father} are for {Eros} ?
Eros is how many people's father?
Eros is the father of how many?
SELECT ( COUNT ( ?y ) AS ?g ) { resource:Eros property:father ?y }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q121973> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P22> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q121973 wdt:P22 ?obj }
6