You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[[9-chloro-7-(5-methylindol-1-yl)spiro[2,3-dihydro-1,4-benzoxazepine-5,3'-oxetane]-4-yl]methyl]-1H-pyridin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H24ClN3O3
assistant