#include <fstream>
#include <vector>
#include <queue>
#include <set>
using namespace std;
ifstream fin("biconex.in");
ofstream fout("biconex.out");

vector<int>component[100001];
vector<pair<int,int> > st;
vector<int>g[100001];
bool vis[100001];
int niv[100001], n, m, x, y, k;

void MakeComponents(int x, int father , int level)
{
    vis[x]=1;
    niv[x]=level;
    for(vector<int>::iterator it=g[x].begin(); it<g[x].end(); it++ )
    {
        if(!vis[*it])
        {
            st.push_back(make_pair(x,*it));
            MakeComponents(*it,x,level+1);
            if(niv[*it]>=level)
            {
                pair<int,int>extract;
                do
                {
                    extract=st.back();
                    st.pop_back();
                    component[k].push_back(extract.second);
                }while(extract.first!=x||extract.second!=*it);
                component[k].push_back(extract.first);
                k++;
            }
        }
        if(*it!=father)
            niv[x]=min(niv[x],niv[*it]);
    }
}

int main()
{
    fin>>n>>m;
    for(int i = 1; i<= m; i++ )
    {
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    MakeComponents(1,0,1);
    fout<<k<<'\n';
    for(int i = 0; i< k; i++ )
    {
        for(vector<int>::iterator it=component[i].begin(); it!=component[i].end(); it++ )
            fout<<*it<<' ';
        fout<<'\n';
    }
    fin.close();
    fout.close();
    return 0;
}