You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-(4-fluorophenyl)-4-methyl-3-(3-methylbutyl)-5-[3-(4-methylphenyl)-1,2,4-oxadiazol-5-yl]-1,6-dihydropyrimidine-2-thione is the IUPAC name of a molecule. Please give its molecular formula.
user
C25H27FN4OS
assistant