You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[[[3-(3-bromophenyl)-1,2,4-oxadiazol-5-yl]methyl-(furan-2-ylmethyl)amino]methyl]phenol by IUPAC nomenclature, provide its molecular formula.
user
C21H18BrN3O3
assistant