You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl 3-(ethoxycarbonylamino)-3-(1H-indol-3-yl)-5-methoxy-2-oxoindole-1-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C25H27N3O6
assistant