You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 1-[1-(4-bromophenyl)pyrrolidin-3-yl]-2-methyl-3-[2-(1-methylpyrazol-4-yl)ethyl]guanidine into molecular formula.
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C18H25BrN6
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