You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(3aR,7S,7aS)-2-benzyl-3,3a,4,6,7,7a-hexahydro-1H-pyrano[3,4-c]pyrrol-7-yl]-N-(cyclopropylmethyl)acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H28N2O2
assistant