You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 3-[4-[(Z)-3-(4-chloro-3-nitrophenyl)-3-oxoprop-1-enyl]-3,5-dimethylpyrazol-1-yl]propanoate is the IUPAC name of a molecule. Please give its molecular formula.
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C18H18ClN3O5
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