You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl 15-formyl-10-oxo-16-propylsulfanyl-18-thia-2,9-diazatetracyclo[9.7.0.03,9.012,17]octadeca-1(11),2,12(17),15-tetraene-6-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H26N2O4S2
assistant