[{"sectionTitle":"题目描述","type":"Text","text":"原题来自：POJ 3764\r\n\r\n给定一棵 $n$ 个点的带权树，求树上最长的异或和路径。","subType":"markdown"},{"sectionTitle":"输入格式","type":"Text","text":"第一行一个整数 $n$，接下来 $n-1$ 行每行三个整数 $u,v,w$，表示 $u,v$ 之间有一条长度为 $w$ 的边。","subType":"markdown"},{"sectionTitle":"输出格式","type":"Text","text":"输出一行一个整数，表示答案。","subType":"markdown"},{"sectionTitle":"样例","type":"Sample","text":"最长的异或和路径是 $1\\to 2\\to 3$ ，它的长度是 $3 \\bigoplus 4=7$。\n\n注意：结点下标从 $1$ 开始到 $N$。\n\n注：$x \\bigoplus y$ 表示 $x$ 与 $y$ 按位异或。","subType":"markdown","payload":["4\n1 2 3\n2 3 4\n2 4 6","7"]},{"sectionTitle":"数据范围与提示","type":"Text","text":"对于 $100\\%$ 的数据，$1\\le n\\le 10^5,1\\le u, v \\le n,0 \\le w < 2^{31}$","subType":"markdown"}]