You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(4-chlorophenyl)-5-[1-(phenylcarbamoyl)pyrrolidin-2-yl]-1,3,4-thiadiazole-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H18ClN5O2S
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