You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name [2-[[(2S)-2-cyano-3-methylbutan-2-yl]amino]-2-oxoethyl] 4-(3,4-dihydro-2H-1,5-benzodioxepin-7-yl)-4-oxobutanoate into its molecular formula.
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C21H26N2O6
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