#include<fstream>
#include<vector>
#include<stack>
#define NMAX 100005
using namespace std;
ifstream cin("biconex.in");
ofstream cout("biconex.out");
vector<int> G[NMAX], bc[NMAX];
stack<pair<int, int> > s;
int n, m, x, y, nrbc;
int niv[NMAX], low[NMAX];
int i, j;
void biconex(int nod, int fiu)
{
    nrbc++;
    do
    {
        x = s.top().first;
        y = s.top().second;
        bc[nrbc].push_back(y);
        s.pop();
    }
    while(x != nod && y != fiu);
    bc[nrbc].push_back(x);
}
void dfsbc(int nod, int tata, int lvl)
{
    niv[nod] = low[nod] = lvl;
    for(int i = 0; i < G[nod].size(); i++)
    {
        int fiu = G[nod][i];
        if(fiu != tata)
        {
            if(niv[fiu] == 0)
            {
                s.push(make_pair(nod, fiu));
                dfsbc(fiu, nod, lvl + 1);
                low[nod] = min(low[fiu], low[nod]);
                if(low[fiu] >= niv[nod])
                {
                    biconex(nod, fiu);
                }
            }else
            {
                low[nod] = min(niv[fiu], low[nod]);
            }
        }
    }
}
int main()
{
    cin >> n >> m;
    for(i = 1; i <= m; i++)
    {
        cin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i = 1; i <= n; i++)
    {
        if(niv[i] == 0)
        {
            dfsbc(i, 0, 1);
        }
    }
    cout << nrbc << "\n";
    for(i = 1; i <= nrbc; i++)
    {
        for(j = 0; j < bc[i].size(); j++)
        {
            cout << bc[i][j] << " ";
        }
        cout << "\n";
    }
    return 0;
}