#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<vector>
#include<queue>
#include<set>
#include<string>

const int maxn = 100000 + 5;
using namespace std;

#define rep(i, j, k) for(int i = j; i <= k; i++)
#define drep(i, j, k) for(int i = j; i >= k; i--)
#define INF 0x3fffffff

inline int read()
{
	int x = 0, f = 1;
	char ch = getchar();
	while(ch < '0' || ch > '9') {if( ch == '-') f = -1; ch = getchar();}
	while(ch >= '0' && ch <= '9') {x = x * 10 + ch - '0'; ch = getchar();}
	return x * f;
}

vector<int>G[maxn];
int m, n, Ar, Sa, s, t, La;
int ans[maxn];

void add(int from, int to)
{
	G[from].push_back(to);
	G[to].push_back(from);
}

bool endd()
{
	rep(i, 1, n) 
		if( G[i].size() < 3) {
			return true;
		}
	return false;
}

int main()
{
	freopen("asm_game.in", "r", stdin);
	freopen("asm_game.out", "w", stdout);
	n = read(); m = read();
	if(n <= 3) {
		printf("%d\n", 0);
		return 0;
	} 
	rep(i, 1, m) {
		Ar = read(); Sa = read();
		add(Ar, Sa);
	}
	int temp = 0;
	//rep(i, 1, n) cout<<G[i].size()<<endl;
	
	while( !endd() ) {
		rep(i, 0, n - 1) 
			if( G[i].size() < 3) {
				rep(j, 0, G[i].size() - 1) {
					int e = G[i][j];
					G[e].erase(remove(G[e].begin(), G[e].end(), e), G[e].end());
				}	
				G[i].clear();
			}
			
				
	}
	int cnt = 0;
	rep(i, 0, n - 1) {
		if( G[i].size() ) ans[++cnt] = i;
	}
	//rep(i, 0, cnt - 1) printf("%d\n", ans[i]);
	rep(i, 0, cnt - 1) La ^= ans[i];
	printf("%d\n" ,La);
	return 0;
}