You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (5S)-7-(3-methoxyphenyl)sulfonyl-1-(pyridin-4-ylmethyl)-1,7-diazaspiro[4.4]nonan-2-one .
user
C20H23N3O4S
assistant