You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N,N-dimethyl-2-[2-[(8S)-2-([1,2,4]triazolo[4,3-b]pyridazin-6-yl)-5-oxa-2-azaspiro[3.5]nonan-8-yl]ethoxy]acetamide by IUPAC nomenclature, provide its molecular formula.
user
C18H26N6O3
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