You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(5-pyrazin-2-yl-2,3-dihydro-1-benzofuran-2-yl)methyl]-2-[3-(trifluoromethyl)phenyl]acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H18F3N3O2
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