You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 9-[(1-ethylimidazol-2-yl)methyl]-2-(2-pyridin-2-ylethyl)-2,9-diazaspiro[5.5]undecan-3-one into its molecular formula.
user
C22H31N5O
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