#include<bits/stdc++.h>
using namespace std;
const int maxn=1e5+10;
int read(){
    int x=0,w=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*w;
}
int n,m,ans;
int deg[maxn],vis[maxn];
vector<int>g[maxn];
void addedge(int u,int v){
    g[u].push_back(v);
    g[v].push_back(u);
}
queue<int>q;
int main(){
    freopen("asm_game.in","r",stdin);
    freopen("asm_game.out","w",stdout);
    n=read(),m=read();
    for(int i=1;i<=m;i++){
        int u=read(),v=read();
        deg[u]++,deg[v]++;
        addedge(u,v);
    }
    for(int i=1;i<=n;i++)if(deg[i]<3)q.push(i),vis[i]=1;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        int len=g[u].size();
        for(int i=0;i<len;i++){
            int v=g[u][i];
            if(!vis[v]&&(--deg[v])<3)q.push(v),vis[v]=1;
        }
    }
    for(int i=1;i<=n;i++)if(!vis[i])ans^=i;
    cout<<ans<<"\n";
}