You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[2-(1-benzothiophen-2-yl)-2-hydroxyethyl]-1-[2-(3,6-dihydro-2H-pyran-4-yl)ethyl]-3-ethylguanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H27N3O2S
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