You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(7R)-9-(3,5-dimethylphenyl)-1,7-dimethyl-3-[(3-methylphenyl)methyl]-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H29N5O2
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