You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 3-[(5-chloro-8-fluoroquinolin-4-yl)amino]-5-(2,3-difluoropyridin-4-yl)-2-nitrobenzoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H12ClF3N4O4
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