#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>

using std::queue;
const int maxn = 1e5 + 5;
const int maxm = 5e5 + 5;
bool vis[maxn];
int n, m, tot, head[maxn], deg[maxn];

template <class T>
inline T read(T &x) {
	x = 0; int w = 1, ch = getchar();
	for (; ch < '0' || ch > '9'; ch = getchar()) if (ch == '-') w = -1;
	for (; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - 48;
	return x *= w;
}

struct Edge {
	int from, to, nxt;
	Edge(int _fr, int _to, int _nxt) {
		this -> from = _fr;
		this -> to = _to;
		this -> nxt = _nxt;
	} Edge() {}
}edge[maxm << 1];
 
void add(int from, int to) {edge[++tot] = Edge(from, to, head[from]), head[from] = tot;}

void nmd_topo() {
	queue<int>q;
	for (int i = 1; i <= n; i++) 
		if (deg[i] < 3) vis[i] = true, q.push(i);
	while (!q.empty()) {
		int u = q.front();
		q.pop();
		for (int i = head[u]; i; i = edge[i].nxt) {
			int v = edge[i].to;
			if (vis[v]) continue;
			deg[v]--;
			if (deg[v] < 3) vis[v] = true, q.push(v);
		}
	}
}
 
int main() {
	freopen("asm_game.in", "r", stdin);
	freopen("asm_game.out", "w", stdout);
	read(n), read(m); int x, y;
	for (int i = 1; i <= m; i++) {
		read(x), read(y);
		add(x, y), add(y, x);
		++deg[x], ++deg[y];
	}
	nmd_topo();
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		if (vis[i]) continue;
		ans = ans ^ i;
	}
	printf("%d\n", ans);
	return 0;
}

/*
6 10
1 2
1 3
1 4
2 3
2 4
3 4
5 2
5 3
5 6
6 2
复杂度O(玄学)
*/