You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule ethyl 1-acetyl-6,8-dioxo-7-(2,4,6-trimethylphenyl)-1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylate into molecular formula.
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C20H23N3O5
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