You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (5Z)-3-(3-chloro-4-fluorophenyl)-5-[(3-ethoxy-4-propoxyphenyl)methylidene]-2-sulfanylidene-1,3-thiazolidin-4-one .
user
C21H19ClFNO3S2
assistant