You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 3-methyl-8-[4-(3-methyl-5-nitropyridin-2-yl)piperazin-1-yl]sulfonylquinoline is given. What is its corresponding molecular formula?
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C20H21N5O4S
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