You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[[4-[(4-chlorophenyl)methoxy]phenyl]methylidene]-3-(2-methoxyethyl)-2-sulfanylidene-1,3-thiazolidin-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H18ClNO3S2
assistant