You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl 5-chloro-3-oxa-11-azatricyclo[6.4.1.04,13]trideca-4,6,8(13)-triene-11-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H20ClNO3
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