You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R)-3-[[2-[4-(trifluoromethyl)pyridin-2-yl]-[1,2,4]triazolo[1,5-c]quinazolin-5-yl]amino]azepan-2-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H18F3N7O
assistant