You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-amino-9-[(1S,6R,8R,9R,10R,15R,17R,18R)-9,18-difluoro-12-hydroxy-17-(6-methylpurin-9-yl)-3-oxo-3-sulfanyl-12-sulfanylidene-2,4,7,11,13,16-hexaoxa-3lambda5,12lambda5-diphosphatricyclo[13.2.1.06,10]octadecan-8-yl]-1H-purin-6-one;2-amino-9-[(1R,6R,8R,9R,10R,15R,17R,18R)-9-fluoro-3,12,18-trihydroxy-17-(6-methylpurin-9-yl)-3,12-bis(sulfanylidene)-2,4,7,11,13,16-hexaoxa-3lambda5,12lambda5-diphosphatricyclo[13.2.1.06,10]octadecan-8-yl]-1H-purin-6-one;methane .
user
C43H51F3N18O19P4S4
assistant