V = (0:-1)[5:4:4] (1:-1)[6:5:5] (2:-1)[7:8:8] (3:-1)[4:3:3] (4:-1)[2:6:6] (5:-1)[8:2:2] (6:-1)[3:1:1] (7:-1)[1:7:7] E = {1,0} (-1) {3,0} (-1) {2,1} (-1) {4,1} (-1) {4,3} (-1) {5,3} (-1) {6,4} (-1) {6,5} (-1) {7,6} (-1)