You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-2-[(1-hydroxypyridin-1-ium-2-yl)methyl]-4-[(2-methylpropan-2-yl)oxy]-4-oxobutanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C14H20NO5+
assistant