You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
8-[(2,5-dimethoxyphenyl)methylsulfinyl]-3-[3-(2-ethylpyridin-4-yl)prop-2-ynyl]-1,7-dimethylpurine-2,6-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H27N5O5S
assistant