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-[(2R)-3-methylbutan-2-yl]-3-[2-methyl-4-[2-(2-oxoimidazolidin-1-yl)ethoxy]phenyl]urea is given. What is its corresponding molecular formula?
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C18H28N4O3
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