You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule cyclobutyl 2-[[[(3S,4S)-5-[2-amino-6-[methanesulfonamido(methyl)amino]purin-9-yl]-3-hydroxy-4-methyloxolan-2-yl]methoxy-(4-bromophenoxy)phosphoryl]amino]-2-methylpropanoate ?
user
C27H38BrN8O9PS
assistant