You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(1S)-1'-(5-bromo-6-methylpyrazin-2-yl)spiro[1,3-dihydroindene-2,4'-piperidine]-1-yl]-2-methylpropane-2-sulfinamide The above is the IUPAC name of a molecule. Write its molecular formula.
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C22H29BrN4OS
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