You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2,5-dimethoxyphenyl)-7-methyl-5-oxo-1-sulfanylidene-5a,6,7,8,9,9a-hexahydro-4H-[1,3]thiazolo[3,4-a]quinazoline-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H23N3O4S2
assistant