You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[[4-(2-azaspiro[4.4]nonan-2-yl)-6-(oxolan-3-yl)pyrimidin-2-yl]amino]ethanol is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H28N4O2
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