You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(7-methoxy-2,3-dihydro-1H-inden-1-yl)-[8-(trifluoromethyl)-2,3-dihydro-1,4-benzoxazin-4-yl]methanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H18F3NO3
assistant