You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(6aS,8E)-8-ethylidene-4-hydroxy-3-methoxy-5,6a,7,9-tetrahydropyrrolo[2,1-c][1,4]benzodiazepine-6,11-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H16N2O4
assistant