[[], [1], [2, 2], [3, 3, 3], [4, 4, 4, 4]]
[[0], [1], [2, 2], [3, 3, 3], [4, 4, 4, 4]]
[[1], [2, 2], [3, 3, 3], [4, 4, 4, 4]]
[[1], [2, 2], [3, 3, 3], [4, 4, 4, 4], [5, 5, 5, 5, 5]]