You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[(E)-2-(2-chloro-4-fluorophenyl)ethenyl]-5-[(3-methylphenyl)methyl]-1,3,4-oxadiazole by IUPAC nomenclature, provide its molecular formula.
user
C18H14ClFN2O
assistant