#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
#include <bitset>

using namespace std;

const int NMax = 100005;
vector < int > G[NMax], rez[NMax];
stack < pair < int, int > > st;
bitset < NMax > viz;
int N, M, comp_bico, tmp = 1;
int tov[NMax], low[NMax];

void Read()
{
    ifstream fin("biconex.in");


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

void Solve(int nod)
{
    int nr = comp_bico;

     while(!st.empty() && st.top().second!=nod)
    {
      rez[nr].push_back(st.top().second);
      st.pop();
    }

    rez[nr].push_back(st.top().second);
    rez[nr].push_back(st.top().first);
    st.pop();
}

void DFS(int nod, int dad)
{
    tov[nod] = low[nod] = tmp;
    ++tmp;
    viz[nod] = 1;
    vector < int > ::iterator it;
    for(it=G[nod].begin(); it!=G[nod].end(); ++it)
    {
        if(*it == dad)
        {
            continue;
        }

        else if(!viz[*it])
            {
                st.push(make_pair(nod, *it));
                DFS(*it,nod);
                low[nod] = min(low[nod], low[*it]);

                if(low[*it] >= tov[nod])
                {
                    ++comp_bico;
                    Solve(*it);
                }
            }
        else
            low[nod] = min(low[nod], tov[*it]);
    }
}

int main()
{
    Read();

    for(int i=1; i<=N; ++i)
    {
        if(!viz[i])
        {
            DFS(i, 0);
        }
    }

    ofstream fout("biconex.out");
    fout << comp_bico << "\n";
    for(int i=1; i<=comp_bico; ++i)
    {
        vector < int > ::iterator it;
        for(it=rez[i].begin(); it!=rez[i].end(); ++it)
            fout << *it << " ";

        fout << "\n";
    }

    return 0;
}