You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,3R,4R,5R)-5-(6-aminopurin-9-yl)-5-ethyl-2-(hydroxymethyl)-4-methylperoxyoxolan-3-ol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C13H19N5O5
assistant