You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(4-methoxyphenyl)-4-[3-(3-methyl-1,2,4-oxadiazol-5-yl)piperidine-1-carbonyl]pyrrolidin-2-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H24N4O4
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