You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-amino-9-[(2R,4S,5R)-3-chloro-3-(2-chloroethynyl)-4-hydroxy-5-[(1S)-1-hydroxyethyl]oxolan-2-yl]-3H-purine-6-thione is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H13Cl2N5O3S
assistant