You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 3-[(11R,15R)-1,13-diazatetracyclo[7.7.0.02,7.011,15]hexadeca-2,4,6,8-tetraen-8-yl]-4-(1-methylindol-3-yl)pyrrole-2,5-dione;hydrochloride is given. What is its corresponding molecular formula?
user
C27H25ClN4O2
assistant