Organization Law of the General Staff Headquarters of the Ministry of National Defense Article 4

The General Staff Headquarters is authorized to have one Chief of the General Staff with the rank of General/Admiral (3-star general/admiral), one Vice Chief of the General Staff and Executive Officer with the rank of General/Admiral (3-star general/admiral), and two Vice Chief of the General Staff with the rank of Lieutenant General/Vice Admiral (2-star general/admiral).
中文原文 國防部參謀本部組織法第4條
參謀本部置參謀總長一人,上將;副參謀總長執行官一人,上將;副參謀總長二人,均中將。

English translation for reference only; the Chinese text prevails. Not legal advice.