What is the molecular formula of the molecule bis(3-methylbutyl) (2S)-2-[[[(3aS,4S,6S,6aR)-6-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-methoxy-6-methyl-3a,6a-dihydrofuro[3,4-d][1,3]dioxol-4-yl]methoxy-phenoxyphosphoryl]amino]butanedioate ?