#include<cstdio>
#include<vector>
#include<cctype>
#include<queue>
#include<iomanip>
#include<iostream>
#include<map>
#include<cmath>
#include<algorithm>
#define MAXN 1000100
using namespace std;
vector<int> p[MAXN];
int q[MAXN]={0};
long long ans;//30%估计
void work(int a)//删除操作
{
q[a]=-1;
for (int j=0;j<=p[a].size()-1;j++)
{q
[p[a][j]]--;
if (q[p[a][j]]<3&&q[p[a][j]]>=0) 
{
work(p[a][j]);
}
}
	return;
}
int main()
{
	ios::sync_with_stdio(false);
	freopen("asm_game.in","r",stdin);
	freopen("asm_game.out","w",stdout);
	int n,m;
	cin>>n>>m;//边点
	for(int i=1;i<=m;i++)//压边
	{
	int u,v;
	cin>>u>>v;
	p[u].push_back(v);
	p[v].push_back(u);
	q[u]++;
	q[v]++;
	}
	for (int i=1;i<=n;i++)if(q[i]<3)work(i); //判断为非关键
	for (int i=1;i<=n;i++)if(q[i]>=3)ans=ans^i;//保留计算
	cout<<ans;
}