You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-2-cyano-N-(5-ethyl-1,3,4-thiadiazol-2-yl)-3-(3-phenoxyphenyl)prop-2-enamide is the IUPAC name of a molecule. Please give its molecular formula.
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C20H16N4O2S
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