You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(4,6-dimethyl-1,3,5-triazin-2-yl)spiro[1,4-dihydroimidazole-5,3'-1-azabicyclo[2.2.2]octane]-2-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C14H21N7
assistant