You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule benzyl (5R)-7-(3-chloro-4-methylphenyl)-6,8-dioxo-1,2,7-triazaspiro[4.4]non-3-ene-3-carboxylate ?
user
C21H18ClN3O4
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