#include <fstream>
#include <vector>
#include <stack>

using namespace std;

const int NMax = 100010, MMax = 200010;
int N, M;
int low[NMax], nivel[NMax];
int nrbic;
vector <int> G[NMax];
vector <int> ans[NMax];
stack <pair <int, int> > st;

void Read()
{
    ifstream f("biconex.in");
    f >> N >> M;
    for (int i = 1; i <= M; ++ i)
    {
        int x, y; f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    f.close();
}

inline void GetComp(const int node, const int fiu)
{
    ++nrbic;
    pair <int, int> aux;
    do
    {
        aux = st.top();
        st.pop();
        ans[nrbic].push_back(aux.second);

    } while (!st.empty() && aux.first != node && aux.second != fiu);
    ans[nrbic].push_back(aux.first);
}

inline void DFS(const int node, const int father)
{
    low[node] = nivel[node];
    for (vector <int> :: iterator it = G[node].begin(); it != G[node].end(); ++ it)
    {
        if (*it != father)
        {
            if (nivel[*it] == 0)
            {
                nivel[*it] = nivel[node] + 1;
                st.push(make_pair(node, *it));
                DFS(*it, node);
                low[node] = min(low[node], low[*it]);
                if (low[*it] >= nivel[node])
                    GetComp(node, *it);
            }
            else
                low[node] = min(low[node], nivel[*it]);
        }
    }
}

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


void Write()
{
    ofstream g("biconex.out");
    g << nrbic << "\n";
    for (int i = 1; i <= nrbic; ++ i, g << "\n")
        for (vector <int> :: iterator it = ans[i].begin(); it != ans[i].end(); ++ it)
            g << *it << " ";
    g.close();
}

int main()
{
    Read();
    Solve();
    Write();
    return 0;
}