#include <fstream>
#include <vector>
#include <bitset>
#include <stack>
using namespace std;
ifstream fin("biconex.in");
ofstream fout("biconex.out");
const int Nmax=100010;
vector<int>G[Nmax];
bitset<Nmax>viz;
vector<vector<int> >comp;
stack<int>stiva;
int nrcomp,nivel[Nmax],sus[Nmax];
void scoate(int nod,int tata)
{
    vector<int>t;
    t.push_back(tata);
    while(stiva.top()!=nod)
    {
        t.push_back(stiva.top());
        stiva.pop();
    }
    t.push_back(nod);
    stiva.pop();
    comp.push_back(t);
}
void dfs(int nod,int tata)
{
    viz[nod]=1;
    nivel[nod]=nivel[tata]+1;
    sus[nod]=nivel[nod];
    for(vector<int>::iterator it=G[nod].begin();it!=G[nod].end();it++)
    {
        if(*it==tata) continue;
        if(viz[*it]==0)
        {
            stiva.push(*it);
            dfs(*it,nod);
            sus[nod]=min(sus[nod],sus[*it]);
            if(nivel[nod]<=sus[*it])
            {
                scoate(*it,nod);
                nrcomp++;
            }
        }
        else
        {
            sus[nod]=min(sus[nod],nivel[*it]);
        }
    }
}
int main()
{
    int n,m,x,i,y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    nivel[0]=-1;
    for(i=1;i<=n;i++)
    {
        stiva.push(i);
        if(viz[i]==0) dfs(i,0);
        stiva.pop();
    }
    fout<<nrcomp<<"\n";
    for(i=0;i<nrcomp;i++)
    {
        unsigned int dim=comp[i].size();
        for(unsigned j=0;j<dim;j++)
        {
            fout<<comp[i][j]<<" ";
        }
        fout<<"\n";
    }
}