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

using namespace std;

ifstream fin("biconex.in");
ofstream fout("biconex.out");

#define lim 100010
int n,m,dr;
vector <vector <int>> rez;
vector <int> G[lim];
int viz[lim], lvl[lim], minlvl[lim], st[lim];

void dfs (int nod, int dad)
{
    viz[nod]=1;
    st[++dr]=nod;
    lvl[nod]=lvl[dad]+1;
    minlvl[nod]=lvl[nod];
    for (auto it:G[nod])    if (it!=dad)
        if (!viz[it])
        {
            dfs (it, nod);
            minlvl[nod] = min (minlvl[nod], minlvl[it]);
            if (minlvl[it]>=lvl[nod])
            {
                vector <int> aux;
                while (st[dr]!=nod && dr)
                {
                    aux.push_back(st[dr]);
                    dr--;
                }
                aux.push_back(nod);
                rez.push_back(aux);
            }
        }
        else
            minlvl[nod] = min (minlvl[it], minlvl[nod]);
}

int main()
{
    int x,y;
    fin>>n>>m;
    for (int i=1; i<=m; i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for (int i=1; i<=n; i++)
        if (!viz[i])    dfs (i, 0);
    fout<<'\n';
    fout<<rez.size()<<'\n';
    for (auto it:rez)
    {
        for (auto itt:it)
            fout<<itt<<' ';
        fout<<'\n';
    }

    fout.close();
    return 0;
}