You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (5E)-2-(3-chloro-4-methylphenyl)imino-5-[(3-methoxy-4-prop-2-enoxyphenyl)methylidene]-1,3-thiazolidin-4-one by IUPAC nomenclature, provide its molecular formula.
user
C21H19ClN2O3S
assistant