[(2R,3S,5R)-2-[[(2R,3S,5R)-5-(2-amino-6-oxo-3H-purin-9-yl)-2-[[[(2R,3S,5R)-2-[[[(2R,3S,5R)-5-(2-amino-6-oxo-3H-purin-9-yl)-2-[[[(2R,3S,5R)-2-[[[(2R,3S,5R)-2-[[[(2R,3S,5R)-5-(2-amino-6-oxo-3H-purin-9-yl)-2-[[[(2R,3S,5R)-2-[[[(2R,3S,5R)-2-[[[(2R,3S,5R)-5-(2-amino-6-oxo-3H-purin-9-yl)-2-[[(2R,3S,5R)-5-(2-amino-6-oxo-3H-purin-9-yl)-2-(phosphonooxymethyl)oxolan-3-yl]oxymethoxymethyl]oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]-5-(2-imino-6-oxo-3H-purin-9-yl)oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]oxolan-3-yl]oxymethoxymethyl]-5-(2-imino-6-oxo-3H-purin-9-yl)oxolan-3-yl] [(2R,3S,5R)-3-[[(2R,3S,5R)-3-[[(2R,3S,5R)-3-[[(2R,3S,5R)-5-(2-amino-6-oxo-3H-purin-9-yl)-3-hydroxyoxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(2-imino-6-oxo-3H-purin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-2-yl]methyl hydrogen phosphate