You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name N-[[1-(2-chloro-8,8-dimethyl-6,7-dihydro-5H-quinazolin-4-yl)piperidin-4-yl]methyl]acetamide into its molecular formula.
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C18H27ClN4O
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