You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl 5,10,10-trimethyl-6-azatricyclo[7.1.1.02,7]undeca-2,4,6-triene-4-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H21NO2
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