[[4, 8], [5, 9], [4, 9], [2, 7], [6, 7], [7, 10], [1, 5], [6, 9], [8, 9], [2, 4]]
[[1, 5, 9, 4, 6, 8, 2, 7, 10], [3]]
1
[[1, 3]]