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 2-(3-methoxyphenoxy)-3-[(3S)-1-[(3-methylimidazol-4-yl)methyl]piperidin-3-yl]pyrazine is given. What is its corresponding molecular formula?
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C21H25N5O2
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