What is the {gravity dam} with the {MAX(hydraulic head)} ?
WHAT IS THE GRAVITY DAM WITH THE MAXIMUM HYDRAULIC HEAD
select ?ent where { ?ent wdt:P31 wd:Q3497167 . ?ent wdt:P4441 ?obj } ORDER BY DESC(?obj)LIMIT 5 
select ?ent where {
?ent <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q3497167>.
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P4441>.
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .}
ORDER BY DESC(?obj)
LIMIT 5
What gravity dam has the maximum hydraulic head?