You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3-hydroxy-3-methyl-7-azaspiro[3.5]nonan-7-yl)-[5-methyl-4-(pyrazol-1-ylmethyl)-1,2-oxazol-3-yl]methanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H24N4O3
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