You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-ethyl-3-oxo-4-[[3-(trifluoromethyl)phenyl]methyl]-5H-1,4-benzoxazepin-7-yl]-2,6-difluorobenzamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H21F5N2O3
assistant