You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[1-(difluoromethyl)benzimidazol-2-yl]methyl 5-ethoxy-3-methyl-1-benzofuran-2-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H18F2N2O4
assistant