You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 1-[1-(4-ethylphenyl)-2-hydroxyethyl]-3-(4-ethynyl-2,6-difluorophenyl)urea is given. What is its corresponding molecular formula?
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C19H18F2N2O2
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