#include <fstream>
#include <vector>
#include <stack>
#define NMAX 100005

using namespace std;

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

vector <int> adj[NMAX];
int disc[NMAX], minn[NMAX];
int timp, cnt_cmp = 0;
bool art[NMAX];
vector <int> conex[NMAX];
stack <int> st;

void adauga(int x, int y, int nr)
{
    while (st.top() != y)
    {
        conex[nr].push_back(st.top());
        st.pop();
    }
    conex[nr].push_back(y);
    st.pop();
    conex[nr].push_back(x);
}

void dfs(int nod, int last)
{
    ++timp;
    disc[nod] = minn[nod] = timp;
    int nr = 0;
    st.push(nod);
    for (int i = 0; i < adj[nod].size(); ++i)
    {
        int vecin = adj[nod][i];
        if (vecin != last)
        {
            if (disc[vecin] == 0)
            {
                dfs(vecin, nod);
                ++nr;
                minn[nod] = min(minn[nod], minn[vecin]);

                if (minn[vecin] >= disc[nod])
                {
                    ++cnt_cmp;
                    adauga(nod, vecin, cnt_cmp);
                    //art[nod] = true;
                }
            }
            else
            {
                minn[nod] = min(minn[nod], disc[vecin]);
            }
        }
    }
}

int main()
{
    int n, m, i, j, a, b;
    in >> n >> m;
    for (i = 1; i <= m; ++i)
    {
        in >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    for (i = 1; i <= n; ++i)
    {
        if (disc[i] == 0)
        {
            dfs(i, 0);
        }
    }

    out << cnt_cmp << '\n';
    for (i = 1; i <= cnt_cmp; ++i)
    {
        for (j = 0; j < conex[i].size(); ++j)
            out << conex[i][j] << " ";
        out << '\n';
    }
    return 0;
}