You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[2-(2-methoxyphenyl)ethyl]-6-methylsulfanyl-N-prop-2-enylpyrazolo[3,4-d]pyrimidin-4-amine into its molecular formula.
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C18H21N5OS
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