You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl 3-(3-methyl-3,4-dihydro-2H-chromen-7-yl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H30N2O3
assistant