You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-amino-9-[(2R,3R,4S,5R)-3,4-dihydroxy-5-[[(Z)-octadec-9-enoxy]methyl]oxolan-2-yl]-1H-purin-6-one by IUPAC nomenclature, provide its molecular formula.
user
C28H47N5O5
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