You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-(3-chlorophenyl)-3-[[(E)-3-(2-ethyl-1-benzofuran-3-yl)prop-2-enoyl]amino]thiourea into its molecular formula.
user
C20H18ClN3O2S
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