You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[[(1R)-1-[(3S)-5-(2-amino-6-sulfanylidene-3H-purin-9-yl)-4-ethynyl-4-fluoro-3-hydroxyoxolan-2-yl]ethoxy]-hydroxyphosphoryl] phosphono hydrogen phosphate is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H17FN5O12P3S
assistant