路径最大异或和

#include<bits/stdc++.h>
#define int long long
#define enel "\n"
#define MOD 1000000007
using namespace std;
const int MAXN=50000;
const int MAXL=60;
struct NOTE
{
	signed v;
	int s;
};
vector<NOTE> e[MAXN+5];
int tot[MAXN+5];
int a[MAXL+5];
int n,m,ans;
bool book[MAXN+6];
void insert(int num)
{
	for(int j=60;j>=0;j--)
	{
		if(!num)
			return;
		if(!(num&(1ll<<j)))
			continue;
		if(a[j]!=0)
		{
			num=num^a[j];
			continue;
		}
		for(int k=0;k<j;k++)
			if(num&(1ll<<k))
				num=num^a[k];
		for(int k=j+1;k<=60;k++)
			if(a[k]&(1ll<<j))
				a[k]=a[k]^num;
		a[j]=num;
		break;
	}
	return;
}
void dfs(int now,int sum)
{
	book[now]=true;
	tot[now]=sum;
	for(int i=0;i<e[now].size();i++)
	{
		signed v=e[now][i].v;
		int w=e[now][i].s;
		if(book[v])
		{
			insert(sum ^ w ^ tot[v]);
			continue;
		}
		dfs(v,sum^w);
	}
	return;
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>n>>m;
	for(int i=1;i<=m;i++)
	{
		int u,v,x;
		cin>>u>>v>>x;
		e[u].push_back((NOTE){v,x});
		e[v].push_back((NOTE){u,x});
	}
	dfs(1,0);
	ans=tot[n];
	for(int i=0;i<=MAXL;i++)
		ans=max(ans,ans^a[i]);
	cout<<ans<<endl;
	return 0;
}