You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 4-[4-(2-methoxyethyl)piperazin-1-yl]-3-nitro-N-(pyridin-2-ylmethyl)benzenesulfonamide by IUPAC nomenclature, provide its molecular formula.
user
C19H25N5O5S
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