Bit Twister on a Tree

You are given a rooted tree consisting of n nodes, numbered 1 through n. Each of the nodes has an integer Ai assigned to it. Let's define children(v) as a sequence of the children of v placed in the increasing order of their ids. Let's define children(v, d) as the following: - children(v, 0) = [v] - children(v, 1) = children(v) - children(v, d) = children(children(v)[1], d - 1) + children(c