You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 5-chloro-3-cyano-N-[2-fluoro-5-[5-(furan-2-yl)-1,3,4-oxadiazol-2-yl]phenyl]-2-methoxybenzamide into molecular formula.
user
C21H12ClFN4O4
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