You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 7-[hydroxy-[hydroxy-[hydroxy-[[(2R,5S)-3-hydroxy-4,5-dimethyloxolan-2-yl]methoxy]phosphoryl]oxyphosphoryl]oxyphosphoryl]oxy-3-oxophenoxazine-4-carboxylic acid .
user
C20H22NO16P3
assistant