You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[6-[4-(7-ethyl-5,6,7,8-tetrahydroquinazolin-4-yl)-3,5-dihydro-2H-1,4-benzoxazepin-7-yl]-1H-imidazo[4,5-b]pyridin-2-yl]ethanamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H31N7O
assistant