You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[4-(difluoromethoxy)-3-ethoxyphenyl]-5,6,7,8-tetrahydro-4aH-[1]benzothiolo[2,3-d]pyrimidin-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H18F2N2O3S
assistant