You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule [[(2R,3R,4S,5R)-5-[2-chloro-6-(cyclopropylmethylamino)purin-9-yl]-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-hydroxyphosphoryl]methylphosphonic acid .
user
C15H21ClFN5O8P2
assistant