3764：The xor-longest Path

In an edge-weighted tree, the xor-length of a path p is defined as the xor sum of the weights of edges on p:

__poj_jax_start___{xor}length(p)=\oplus_{e \in p}w(e)__poj_jax_end__

⊕ is the xor operator.

We say a path the xor-longest path if it has the largest xor-length. Given an edge-weighted tree with n nodes, can you find the xor-longest path? 　

The input contains several test cases. The first line of each test case contains an integer n(1<=n<=100000), The following n-1 lines each contains three integers u(0 <= u < n),v(0 <= v < n),w(0 <= w < 2^31), which means there is an edge between node u and v of length w.

The xor-longest path is 0->1->2, which has length 7 (=3 ⊕ 4)