You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-[2-(4-ethylpiperazin-1-yl)propyl]-2-methyl-3-[(2-methylpyrazol-3-yl)methyl]guanidine by IUPAC nomenclature, provide its molecular formula.
user
C16H31N7
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