You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[3-methoxy-4-(1,3-oxazol-5-yl)phenyl]-2-[(2S)-1-(2-methylpropanoyl)pyrrolidin-2-yl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H25N3O4
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