You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name N-[1-[1-(2,5-dimethylthiophen-3-yl)ethylamino]-4-methylsulfanyl-1-oxobutan-2-yl]-3-methylbenzamide into its molecular formula.
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C21H28N2O2S2
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