#include<cstdio>
#include<deque>
#include<iostream>
using namespace std;
const int SIZEN=100010,SIZEM=500000;
int N,M;
int d[SIZEN]={0};
bool H[SIZEN]={0};
deque<int> s[SIZEN],Q;
void read()
{
	scanf("%d%d",&N,&M);
	int fr,to;
	for(int i=1;i<=M;i++)
	{
		scanf("%d%d",&fr,&to);
		s[fr].push_back(to);
		s[to].push_back(fr);
		d[fr]++,d[to]++;
	}
}
void tp()
{
	while(!Q.empty())
	{
		int x=Q.front();Q.pop_front();
		//cout<<x<<endl;
		H[x]=1;
		for(int i=0;i<s[x].size();i++)
		{
			int v=s[x][i];
			if(H[v]) continue;
			d[v]--;
			if(d[v]<3) Q.push_back(v);
		}
	}
}
void work()
{
	for(int i=1;i<=N;i++) if(d[i]<3) Q.push_back(i);
	tp();
	int ans=0;
	for(int i=1;i<=N;i++) if(H[i]==0) ans^=i;
	printf("%d\n",ans);
}
int main()
{
	freopen("asm_game.in","r",stdin);
	freopen("asm_game.out","w",stdout);
	read();
	work();
	return 0;
}