You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
benzyl N-[9-[hydroxy-(2-hydroxyethylamino)methyl]-1-methyl-6-phenyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]carbamate is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H28N6O4
assistant