You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (5E)-5-[(3-chloro-5-ethoxy-4-prop-2-enoxyphenyl)methylidene]-3-phenyl-2-sulfanylidene-1,3-thiazolidin-4-one .
user
C21H18ClNO3S2
assistant