You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R)-7-chloro-1-[[2-(2-chlorophenyl)-5-methyl-1,3-oxazol-4-yl]methyl]-5-(2-fluorophenyl)-3-methyl-3H-1,4-benzodiazepin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H20Cl2FN3O2
assistant