You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-[(E)-4-ethoxy-2-hydroxy-2-(trifluoromethyl)but-3-enyl]-3-(3-ethynylphenyl)urea by IUPAC nomenclature, provide its molecular formula.
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C16H17F3N2O3
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