You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 1-[2-(3,4-dimethoxyphenyl)ethyl]-2-[[1-(2-ethoxyethyl)cyclopropyl]methyl]-3-ethylguanidine is given. What is its corresponding molecular formula?
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C21H35N3O3
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