You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl (1S,2R)-2-[[4-[3-[bis(4-chlorophenyl)methoxy]propyl]piperazin-1-yl]methyl]cyclopropane-1-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H34Cl2N2O3
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