You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(Z)-[14-(4-bromobenzoyl)-18-ethyl-8-oxo-4-oxa-18-azatetracyclo[9.7.0.03,9.012,17]octadeca-1,3(9),10,12(17),13,15-hexaen-7-ylidene]amino] acetate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H21BrN2O5
assistant