You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (4S)-1-(pyridin-4-ylmethyl)-4-[4-(1H-1,2,4-triazol-5-yl)piperidine-1-carbonyl]pyrrolidin-2-one by IUPAC nomenclature, provide its molecular formula.
user
C18H22N6O2
assistant