You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-3-[3a-methyl-1-(naphthalen-2-ylmethyl)-2-oxo-3,4,5,6-tetrahydroindol-7-yl]prop-2-enoic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H23NO3
assistant