You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[3-(4-chlorophenyl)prop-1-ynyl]-3-[2-(3,4-difluorophenyl)ethyl]-1H-quinazolin-3-ium-2,4-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C25H18ClF2N2O2+
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