You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[(3S)-3-(4-chlorophenyl)-2-ethyl-3H-1,2,4-oxadiazol-5-yl]-N-ethylpropan-1-amine is the IUPAC name of a molecule. Please give its molecular formula.
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C15H22ClN3O
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