Description：

Solution：

Code：

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstdio>

#include<cmath>

#include<cctype>

#include<cstring>

using namespace std;

int n,m;

#define MAXN 100010

struct edges

{

	int u,v,w;

}es[MAXN];

bool tag[MAXN];

int f[MAXN];

int find(int x){return (x == f[x] ? x : f[x] = find(f[x]));}

struct LinearBase

{

	int d[29];

	void insert(int x)

	{

		for(int i = 28;i >= 0;--i)

		{

			if(x & (1 << i))

			{

				if(d[i] == 0)

				{

					d[i] = x;

					break;

				}

				else

				{

					x ^= d[i];

				}

			}

		}

		return;

	}

	int query(int x)

	{

		for(int i = 28;i >= 0;--i)

		{

			if((x ^ d[i]) < x)

			{

				x ^= d[i];

			}

		}

		return x;

	}

}s;

struct edge

{

	int to,nxt,v;

}e[MAXN << 1];

int edgenum = 0;

int lin[MAXN] = {0};

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

{

	e[++edgenum] = (edge){b,lin[a],c};lin[a] = edgenum;

	e[++edgenum] = (edge){a,lin[b],c};lin[b] = edgenum;

	return;

}

int val[MAXN];

bool v[MAXN];

void dfs(int k)

{

	v[k] = true;

	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()

{

	scanf("%d%d",&n,&m);

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

	{

		scanf("%d%d%d",&es[i].u,&es[i].v,&es[i].w);

	}

	for(int i = 1;i <= n;++i)f[i] = i;

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

	{

		int p = find(es[i].u),q = find(es[i].v);

		if(p == q)continue;

		add(es[i].u,es[i].v,es[i].w);

		f[p] = q;

	}

	dfs(1);

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

	{

		s.insert(val[es[i].u] ^ val[es[i].v] ^ es[i].w);

	}

	cout << s.query(val[1] ^ val[n]) << endl;

	return 0;

}