You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-methyl-N-[(2-methylphenyl)methyl]-5-methylsulfonyl-4-[(3S)-piperidin-3-yl]pyrimidin-2-amine by IUPAC nomenclature, provide its molecular formula.
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C19H26N4O2S
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