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