You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-ethyl-2-[2-(4-methylpiperidin-1-yl)propyl]-3-(1-propanoylpyrrolidin-3-yl)guanidine by IUPAC nomenclature, provide its molecular formula.
user
C19H37N5O
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