You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[(2S)-1-[(2-ethyl-4-oxooxolan-3-yl)amino]-4,4-dimethyl-1-oxopentan-2-yl]benzamide into molecular formula.
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C20H28N2O4
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