You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S,3R,4S,5R)-2-(6-amino-1-oxido-1,2,3,4,5,6,7,8-octahydropurin-1-ium-9-yl)-5-(hydroxymethyl)oxolane-3,4-diol is the IUPAC name of a molecule. Please give its molecular formula.
user
C10H21N5O5
assistant