You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[(4S,4aS,5S,6R,8aS)-6-[(2S)-1-[2-cyanoethyl(methyl)amino]-1-oxopropan-2-yl]-5-hydroxy-4,8a-dimethyl-4a,5,6,7,8,9-hexahydro-4H-benzo[f][1,3]benzothiazol-2-yl]-3,3-dimethylbutanamide by IUPAC nomenclature, provide its molecular formula.
user
C26H40N4O3S
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