You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name N-(3-chloro-4-methoxyphenyl)-2-[3-(5-methyl-1,3,4-oxadiazol-2-yl)indol-1-yl]acetamide into its molecular formula.
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C20H17ClN4O3
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