You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule N-[[(1R,3aR,7aR)-5-(oxolan-3-ylmethyl)-3,3a,4,6,7,7a-hexahydro-1H-furo[3,4-c]pyridin-1-yl]methyl]-1-methylimidazole-2-carboxamide into molecular formula.
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C18H28N4O3
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