You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(6R)-4-[2-[4-(4-methoxyphenyl)piperazin-1-yl]-2-oxoethyl]-11-methyl-1-oxa-4,11-diazaspiro[5.6]dodec-8-en-12-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H32N4O4
assistant