You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (2R)-2-[(3-methyl-4-oxo-5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-2-yl)sulfanyl]-N-(2-methylphenyl)propanamide into its molecular formula.
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C21H23N3O2S2
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