You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(2,3-difluorophenyl)-N-[(7-pyridin-4-yl-2,3-dihydro-1-benzofuran-2-yl)methyl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H18F2N2O2
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