You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-hydroxy-N-[(E)-(4-methoxyphenyl)methylideneamino]-2-methyl-1,1-dioxo-1lambda6,2-benzothiazine-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H17N3O5S
assistant