You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1S,2R,5R)-5-(6-amino-2-chloropurin-9-yl)-3-(hydroxymethyl)cyclopent-3-ene-1,2-diol is the IUPAC name of a molecule. Please give its molecular formula.
user
C11H12ClN5O3
assistant