You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named N-[4-(tert-butylcarbamoyl)phenyl]-4-pyridin-3-ylsulfonylpiperazine-1-carboxamide is given. What is its corresponding molecular formula?
user
C21H27N5O4S
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