You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4R)-4-[4-[2-(2,3-dihydro-1-benzofuran-5-yl)ethoxy]phenyl]-3,4-dihydropyrano[3,2-c]chromene-2,5-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H22O6
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