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

using namespace std;

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

int n, m, nivel[100100], nma[100100];
bool viz[100100];
vector<int> graf[100100], componenta;
stack<int> st;
vector<vector<int>> CBC;

void DFS(int nod, int tata)
{
    viz[nod] = 1;
    nivel[nod] = nivel[tata] + 1;
    nma[nod] = nivel[nod];
    st.push(nod);

    for(int i=0;i<graf[nod].size();i++)
        if(graf[nod][i] != tata)
            if(viz[graf[nod][i]])
            {
                if(nma[nod] > nivel[graf[nod][i]])
                    nma[nod] = nivel[graf[nod][i]];
            }
            else
            {
                DFS(graf[nod][i], nod);
                if(nma[nod] > nma[graf[nod][i]])       // actualizare nivel minim accesibil
                    nma[nod] = nma[graf[nod][i]];

                if(nivel[nod] <= nma[graf[nod][i]])                // componente biconexe
                {
                    componenta.clear();
                    while(st.top() != graf[nod][i])
                    {
                        componenta.push_back(st.top());
                        st.pop();
                    }
                    componenta.push_back(st.top());
                    st.pop();
                    componenta.push_back(nod);
                    CBC.push_back(componenta);
                }
            }
}

int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    f.close();

    DFS(1,0);

    g<<CBC.size()<<endl;

    for(int i=0;i<CBC.size();i++)
    {
        for(int j=0;j<CBC[i].size();j++)
            g<<CBC[i][j]<<" ";
        g<<endl;
    }

    g.close();

   /* for(int i=1;i<=n;i++)
        cout<<i<<" -> "<<nivel[i]<<" "<<nma[i]<<endl;*/


    return 0;

}