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 4-[(3S)-3-[(2S)-2-[(5-bromo-6-oxo-1H-pyridazin-4-yl)oxy]-3-methoxypropoxy]-2-oxopyrrolidin-1-yl]pyridine-3-carbonitrile is given. What is its corresponding molecular formula?
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C18H18BrN5O5
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