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 N-(6-chloro-3,4-dihydro-2H-chromen-3-yl)-5-(1,1-difluoroethyl)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-2-carboxamide is given. What is its corresponding molecular formula?
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C18H18ClF2N3O3
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