You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(7-methyl-3,4-dihydro-1H-[1,4]oxazino[4,3-a]benzimidazol-4-yl)methyl]cyclohexanamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H25N3O
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