You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[[3-[(3,5-dimethylphenoxy)methyl]-1,2,4-oxadiazol-5-yl]methyl]-7-fluoro-3,5-dihydro-2H-1,5-benzodiazepin-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H21FN4O3
assistant