You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(Z)-1-chloro-2-(3,5-dimethoxyphenyl)ethenyl]-5-(furan-2-yl)-3H-thieno[2,3-d]pyrimidin-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H15ClN2O4S
assistant