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-[(1S,6R,8R,9R,10S,15R,17R,18R)-17-(2,4-dioxopyrimidin-1-yl)-9,18-dihydroxy-3,12-dioxido-3,12-dioxo-2,4,7,11,13,16-hexaoxa-3lambda5,12lambda5-diphosphatricyclo[13.3.0.06,10]octadecan-8-yl]pyrimidine-2,4-dione is given. What is its corresponding molecular formula?
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C18H20N4O16P2-2
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