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 (Z)-N'-[[(3aR,4R,6R,6aR)-4-(6-aminopurin-9-yl)-2,2-dimethyl-3a,4,6,6a-tetrahydrofuro[3,4-d][1,3]dioxol-6-yl]methyl]-N'-methylbut-2-ene-1,4-diamine .
user
C18H27N7O3
assistant