You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
magnesium;(1,1-dimethylpiperidin-1-ium-3-yl) 2-[oxido(oxo)silyl]oxy-2,2-diphenylacetate;bromide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H25BrMgNO5Si+
assistant