#include<fstream>
#include<vector>
using namespace std;
int timp[100001],b[100001],t,m,n,viz[100001],ar[100001],pred[100001],tata[100001],s[2][200001],nrm,nrcomp;
ifstream fin("biconex.in");
ofstream fout("biconex.out");
vector<int> v[100001];
vector<int> art;
vector<int> bicon[100001];
void citire()
{
    int x,y;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void scoate(int a,int b)
{
    nrcomp++;
    bicon[nrcomp].push_back(s[1][nrm]);
    while(s[0][nrm]!=a || s[1][nrm]!=b)
    {
        bicon[nrcomp].push_back(s[0][nrm]);
        nrm--;
    }
    bicon[nrcomp].push_back(a);
    nrm--;

}


void dfs(int nod)
{
    timp[nod]=++t;
    b[nod]=t;
    for(int i=0;i<v[nod].size();i++)
    {
        if(viz[v[nod][i]]==0)
        {
            nrm++;
            s[0][nrm]=nod;
            s[1][nrm]=v[nod][i];

            pred[nod]++;
            viz[v[nod][i]]=1;
            tata[v[nod][i]]=nod;
            dfs(v[nod][i]);
            if(b[nod]>b[v[nod][i]])
            {
                b[nod]=b[v[nod][i]];
            }
            if(timp[nod]<=b[v[nod][i]] && tata[nod]!=0 && ar[nod]!=1)
            {
                art.push_back(nod);
                ar[nod]=1;
                scoate(nod,v[nod][i]);
            }

        }
        else
        {
            if(b[nod]>timp[v[nod][i]])
            b[nod]=timp[v[nod][i]];
        }
    }
    if(tata[nod]==0  && pred[nod]>=2)
    {
        art.push_back(nod);
        ar[nod]=1;
    }
}

void afisare()
{
    fout<<nrcomp<<"\n";
    for(int i=1;i<=nrcomp;i++)
    {
        for(int j=0;j<bicon[i].size();j++)
        {
            fout<<bicon[i][j]<<" ";
        }
        fout<<"\n";
    }
}

int main()
{
    citire();
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
        }
    }
    afisare();
    return 0;
}