You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[4-[3-(4,6-dimethyl-2-methylsulfanylpyrimidin-5-yl)propanoylamino]phenyl]-3-methylbutanamide by IUPAC nomenclature, provide its molecular formula.
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C21H28N4O2S
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