You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[2-(4-bromophenyl)sulfonylethyl]-3-ethyl-2-[(1-ethylpyrrolidin-2-yl)methyl]guanidine into its molecular formula.
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C18H29BrN4O2S
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