#include<cstdio>
#include<vector>
using namespace std;
vector<int> p[100100];
int l[100100]={0};
void f(int x)
{
	l[x]=-1;
	for (int j=0;j<p[x].size();j++)
	{		
		l[p[x][j]]--;
		if (l[p[x][j]]<3&&l[p[x][j]]>=0) f(p[x][j]);
	}
	return;
}
int main()
{
	freopen("asm_game.in","r",stdin);
	freopen("asm_game.out","w",stdout);
	int n,m;
	scanf("%d%d",&n,&m);
	for (int i=1;i<=m;i++)
	{
		int u,v;
		scanf("%d%d",&u,&v);
		p[u].push_back(v);
		p[v].push_back(u);
		l[u]++;
		l[v]++;
	}
	for (int i=1;i<=n;i++)
		if (l[i]<3) f(i);
	long long ans=0;
	for (int i=1;i<=n;i++)
		if (l[i]>=3) ans=ans^i;
	printf("%d",ans);
}