#include <bits/stdc++.h>

using namespace std;

int N, M, nrBiconexe;
const int Nmax = 100005;
vector<vector<int> > G, bic;
bitset<Nmax> used, articulation;
stack<pair<int,int> > S;
int depth[Nmax], upperMost[Nmax];

void outputSolution()
{
    cout << nrBiconexe << "\n";
    for(int i = 1; i <= nrBiconexe; ++i) {
        for(auto it : bic[i])
            cout << it << " ";
        cout << "\n";
    }
}

void output(int k)
{
    ++nrBiconexe;
    while(true) {
        auto crt = S.top();
        S.pop();
        bic[nrBiconexe].push_back(crt.second);
        if(crt.first == k)
            break;
    }
    bic[nrBiconexe].push_back(k);
}

void DFS(int k, int dad)
{
    used[k] = true;
    depth[k] = depth[dad] + 1;
    upperMost[k] = depth[k];

    for(auto it : G[k])
        if(!used[it]) {
            S.push({k, it});
            DFS(it, k);
            upperMost[k] = min(upperMost[k], upperMost[it]);
            if(upperMost[it] >= depth[k]) /// it is disconected here.
            {
                articulation[k] = true;
                output(k);
            }
        }
        else
            if(it != dad && depth[it] < upperMost[k])
                upperMost[k] = depth[it];
}

int main()
{
    freopen("biconex.in", "r", stdin);
    freopen("biconex.out", "w", stdout);

    cin.sync_with_stdio(false);

    cin >> N >> M;
    G.resize(N + 1); bic.resize(N + 1);

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

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

    outputSolution();

    return 0;
}