You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(5Z)-3-[2-(4-chlorophenoxy)ethyl]-5-[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]-1,3-thiazolidine-2,4-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H18ClNO6S
assistant