Tree: has children . Node has child . Node has child . Query: LCA. Both have . Check up[4][1] = 1, up[5][1] = 1: same, skip.
Check up[4][0] = 2, up[5][0] = 3: different, jump both. Now , . No more bits to check. Return up[2][0] = 1. LCA is . The nodes are in different subtrees, so their meeting point is the root. This example shows how the algorithm handles nodes in separate branches.