You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(2-methyl-6-phenylpyrimidin-4-yl)-3-oxo-2-phenyl-2,4-dihydroquinoxaline-6-sulfonamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C25H21N5O3S
assistant