Question: Who is Yujiulü Nagai's paternal grandfather?
Sentence (from "Yujiulü Nagai"): Yujiulü Nagai (pinyin: Yùjiǔlǘ Nàgài) (?-506) was ruler of the Rouran (492-506) with the title of Houqifudaikezhe Khagan (侯其伏代庫者可汗).
Relevant evidence: No