You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (E)-3-(3-chloro-4-methylphenyl)-N-[(4-pyrrolidin-1-ylsulfonylphenyl)methyl]prop-2-enamide into its molecular formula.
user
C21H23ClN2O3S
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