8 17 0 1 0 5 0 6 1 2 1 6 1 7 2 3 2 6 2 7 3 4 3 7 4 5 4 6 4 7 5 6 5 7 6 7 // // 8 vertices numbered 0 to 7 // 17 edges // An edge (i,j) restricts i and j to take non-sequential values // The 8 vertices have to be labelled differently, with values in the range 0 to 7 // This is the "Crystal Maze" with 8 vertices // // 1 2 // 0 6 7 3 // 5 6 //