You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 4-[1-(difluoromethyl)benzimidazol-2-yl]sulfanyl-2-pyridin-4-ylquinazoline is given. What is its corresponding molecular formula?
user
C21H13F2N5S
assistant