You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[3-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)-3-oxopropyl]-2-methyl-3-(2-phenoxyethyl)guanidine into its molecular formula.
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C20H26N4O2S
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