When was the last paper by Qinghao Hu published?
Report the year in which Hu, Qinghao published their last paper.
SELECT DISTINCT MAX(xsd:integer(?answer)) AS ?answer WHERE { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/169/3407> . ?x <https://dblp.org/rdf/schema#yearOfPublication> ?answer }
<https://dblp.org/pid/169/3407>