#include<set>
#include<map>
#include<stack>
#include<queue>
#include<cmath>
#include<cctype>
#include<cstdio>
#include<string>
#include<vector>
#include<cstring>
#include<cstdlib>
#include<utility>
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
const int INF = 0x3f3f3f3f;
const int maxn = 100010, maxm = 500010;
int n, m, deg[maxn];
vector<int> G[maxn];
bool deled[maxn], ok = false;
void del(int u){
  ok = false;
  deg[u]--; deled[u] = true;
  for(int i = 0; i < G[u].size(); i++){
    int v = G[u][i];
    if(!deled[v] && --deg[v] < 3) del(v);
  }
}
int main()
{
  freopen("asm_game.in", "r", stdin);
  freopen("asm_game.out", "w", stdout);
  cin >> n >> m;
  int u, v;
  memset(deg, 0, sizeof(deg));
  for(int i = 0; i < m; i++){
    scanf("%d%d", &u, &v);
    G[u].push_back(v); deg[u]++;
    G[v].push_back(u); deg[v]++;
  }
  memset(deled, false, sizeof(deled));
  while(!ok){
    ok = true;
    for(int i = 1; i <= n; i++)
      if(!deled[i] && deg[i] < 3) del(i);
  }
  bool first = true;
  int ans = 0;
  for(int i = 1; i <= n; i++)
    if(!deled[i]){
      if(first){
        ans = i;
        first = false;
      }
      else ans = ans ^ i;
    }
  cout << ans << endl;
  return 0;
}