What is the {holding company} with the {MAX(total assets)} whose {owned by} is {BlackRock}  ?
What is the holding company owned by Black Rock with the highest total assets?
select ?ent where { ?ent wdt:P31 wd:Q219577 . ?ent wdt:P2403 ?obj . ?ent wdt:P127 wd:Q219635 } ORDER BY DESC(?obj)LIMIT 5 
select ?ent where {
?ent <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q219577>.

?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2403>.
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj1.

?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P127> .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q219635> .

}
ORDER BY DESC(?obj1)
LIMIT 5
Give me the name of the holding company owned by Black Rock with the highest total assets.