You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
propan-2-yl 6-(5-bromopyridin-2-yl)oxy-4-(methoxymethyl)-9H-pyrido[3,4-b]indole-3-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H20BrN3O4
assistant