You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[[5-(3-oxo-1,3lambda4-benzoxathiol-6-yl)pyrimidin-2-yl]oxymethyl]piperidine-1-carboxylic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H19N3O5S
assistant