#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<vector>
#include<cstdlib>
#include<cstring>
#include<string>
#include<ctime>
using namespace std;
int n,m,a[810];
bool diect[810][810];
int fun(int x)
{
	a[x]=0;
	int ans=x;
	for(int i=1;i<=n;i++)
	{
		if(diect[x][i]&&a[i]>=3)
		{
			ans=ans^fun(i);
		}
	}
//	cout<<x<<" "<<ans<<endl;
	return ans;
}
int main()
{
	freopen("asm_game.in","r",stdin);
	freopen("asm_game.out","w",stdout);
	

	int u,v,start,ans;
	cin>>n>>m;
	for(int i=1;i<=m;i++)
	{
		scanf("%d%d",&u,&v);
		diect[v][u]=1;
		diect[u][v]=1;
		a[u]++;
		a[v]++;
	}
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)
		{
			if(a[i]<3&&diect[i][j])
			{
				a[j]--;
				diect[i][j]=0;
				diect[j][i]=0;
			}
		}
	}
	for(int i=1;i<=n;i++)
	{
		if(a[i]>=3){
			start=i;
			break;
		}
	}
	a[start]=0;
	
	cout<<fun(start);


  

}