You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [(Z)-1-[(3R,8S,9S,10R,13S,14S,16R,17S)-3-acetyloxy-10,13-dimethyl-16-(nitromethyl)-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-17-yl]ethylideneamino] propanoate by IUPAC nomenclature, provide its molecular formula.
user
C27H40N2O6
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