You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[4-[4-[(2R)-2-methylpiperidin-1-yl]sulfonylphenyl]sulfonylpiperazin-1-yl]pyrimidine by IUPAC nomenclature, provide its molecular formula.
user
C20H27N5O4S2
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