#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
ifstream f("pamant.in");
ofstream g("pamant.out");

const int Nmax = 100005;
int n, m, Use[Nmax], nr, nrpct, Level[Nmax], Low[Nmax];
vector <int> G[Nmax], Sol, punct;

void DFS(int nod, int tata)
{
    int nrsons = 0;
    Use[nod] = 1;
    Level[nod] = Level[tata]+1;
    Low[nod] = Level[nod];
    for(int i = 0; i < (int)G[nod].size(); i++)
    {
        int vecin = G[nod][i];
        if(vecin == tata) continue;
        if(!Use[vecin])
        {
            nrsons++;
            DFS(vecin,nod);
            Low[nod] = min(Low[nod], Low[vecin]);
            if(Low[vecin] >= Level[nod] && tata!=0)
            {
                nrpct++;
                punct.push_back(nod);
            }
        }
        else
        {
            Low[nod] = min(Low[nod], Level[vecin]);
        }
    }
    if(tata == 0 && nrsons > 1)
    {
        nrpct++;
        punct.push_back(nod);
    }
}

int main()
{
    f>>n>>m;
    while(m--)
    {
        int x,y;
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(Use[i] == 0)
        {
            nr++;
            Sol.push_back(i);
            DFS(i,0);
        }
    }
    g<<nr<<'\n';
    for(int i = 0; i < (int)Sol.size(); i++) g<<Sol[i]<<' ';
    g<<'\n';
    g<<nrpct<<'\n';
    for(int i = 0; i < (int)punct.size(); i++) g<<punct[i]<<' ';
    g<<'\n';
    return 0;
}