You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named tert-butyl 5-(3,5-difluorophenyl)-2-(oxan-4-yl)-3-oxopiperazine-1-carboxylate is given. What is its corresponding molecular formula?
user
C20H26F2N2O4
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