You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-(2-oxo-1-propan-2-ylpyrrolidin-3-yl)-7a-propyl-6,7-dihydro-5H-pyrrolo[1,2-c]imidazole-1,3-dione into its molecular formula.
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C16H25N3O3
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