You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [2-[5-(2-acetamidoethyl)thiophen-2-yl]-2-oxoethyl] 2-(benzenesulfonamido)-4-methylsulfanylbutanoate by IUPAC nomenclature, provide its molecular formula.
user
C21H26N2O6S3
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