Description：

Solution：

Code：

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstdio>

#include<cmath>

#include<cstring>

using namespace std;

int n;

#define MAXN 100010

typedef unsigned int uint;

struct node

{

	int tr[2];

}t[MAXN * 32];

int ptr = 0;

int newnode(){return ++ptr;}

int root;

void insert(uint k)

{

	int cur = root;

	for(int i = 31;i >= 0;--i)

	{

		if(t[cur].tr[(k >> i) & 1] == 0)t[cur].tr[(k >> i) & 1] = newnode();

		cur = t[cur].tr[(k >> i) & 1];

	}

	return;

}

int query(uint k)

{

	int cur = root;

	uint res = 0;

	for(int i = 31;i >= 0;--i)

	{

		if(t[cur].tr[!((k >> i) & 1)] != 0)

		{

			cur = t[cur].tr[!((k >> i) & 1)];

			res += (1 << i);

		}

		else cur = t[cur].tr[(k >> i) & 1];

	}

	return res;

}

struct edge

{

	int to,nxt;

	uint v;

}e[MAXN << 1];

int edgenum = 0;

int lin[MAXN] = {0};

void add(int a,int b,uint c)

{

	++edgenum;e[edgenum].to = b;e[edgenum].v = c;e[edgenum].nxt = lin[a];lin[a] = edgenum;

	++edgenum;e[edgenum].to = a;e[edgenum].v = c;e[edgenum].nxt = lin[b];lin[b] = edgenum;

	return;

}

bool v[MAXN];

uint val[MAXN];

void dfs(int k)

{

	v[k] = true;

	insert(val[k]);

	for(int i = lin[k];i != 0;i = e[i].nxt)

	{

		if(v[e[i].to])continue;

		val[e[i].to] = val[k] ^ e[i].v;

		dfs(e[i].to);

	}

	return;

}

int main()

{

	while(scanf("%d",&n) != EOF)

	{

		memset(t,0,sizeof(t));

		ptr = 0;

		memset(lin,0,sizeof(lin));

		edgenum = 0;

		int a,b;

		uint c;

		for(int i = 1;i < n;++i)

		{

			scanf("%d%d%d",&a,&b,&c);

			++a;++b;

			add(a,b,c);

		}

		memset(v,false,sizeof(v));

		dfs(1);

		int ans = 0;

		for(int i = 1;i <= n;++i)

		{

			ans = max(ans,query(val[i]));

		}

		cout << ans << endl;

	}

	return 0;

}