#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <queue>
#define Re register
using namespace std;

const int maxn = 500010;

queue<int>Q;

int n, m, u, v;
int cnt, top, ans;
int head[maxn], in[maxn];
bool vis[maxn];

struct Edge{
	int u, v, next;
}e[maxn << 1];

int f_;
char ch_;
template <class T>
	inline T read (T &x_){
		x_ = 0, f_ = 1, ch_ = getchar();
		while (ch_ > '9' || ch_ < '0'){if (ch_ == '-') f_ = -1; ch_ = getchar();}
		while (ch_ >= '0' && ch_ <= '9') x_ = (x_ << 3) + (x_ << 1) + ch_ - 48, ch_ = getchar();
		return x_ *= f_;
	}
	
void add (int u, int v){
	e[++cnt].u = u;
	e[cnt].v = v;
	e[cnt].next = head[u];
	head[u] = cnt;
	return;
}

void Tuopu_sort (){
	for (Re int i = 1;i <= n; ++i){
		if (in[i] < 3) {
			Q.push(i);
			vis[i] = 1;
		}
	}
	while (!Q.empty()){
		top = Q.front();
		Q.pop();
		for (Re int i = head[top]; i;i = e[i].next){
			if (vis[e[i].v]) continue;
			in[e[i].v]--;
			if (in[e[i].v] < 3){
				Q.push(e[i].v);
				vis[e[i].v] = 1;
			}
		}
//		for (register int i = 1;i <= n; ++i) cout << i <<' '<<in[i] << '\n';
//		cout << '\n';
	}
}

int main(){
	freopen ("asm_game.in", "r", stdin);
	freopen ("asm_game.out", "w", stdout);
	read(n);
	read(m);
	for (Re int i = 1;i <= m; ++i){
		read(u); read(v);
		add (u, v);
		add (v, u);
		in[u]++;
		in[v]++;
	}
//	for (register int i = 1;i <= n; ++i) cout << i <<' '<<in[i] << '\n';
	Tuopu_sort();
	for (Re int i = 1;i <= n; ++i){
		if (vis[i]) continue;
		ans ^= i;
	}
	printf ("%d\n", ans);
	return 0;
}