You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-[(3R)-1-[2-[2-(4-bromophenoxy)ethyl-methylamino]-2-oxoethyl]piperidin-3-yl]acetic acid by IUPAC nomenclature, provide its molecular formula.
user
C18H25BrN2O4
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