You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-chloro-9-[(4-methylphenyl)methyl]-4-phenyl-8,10-dihydropyrano[2,3-f][1,3]benzoxazin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C25H20ClNO3
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