#include<bits/stdc++.h>
using namespace std;
ifstream f("biconex.in");
ofstream g("biconex.out");
int low[100005],level[100005];
stack<int>stiva;
vector<int>v[100005];//lista de adiacenta
vector<vector<int> >sol;
void Addcomponent(int x,int y)//adaug o componenta biconexa la solutie
{
    vector<int>aux;
    int a;
    aux.push_back(x);
    do//adaug toate nodurile intermediare intre x si y si inclusiv acestea
    {
        a=stiva.top();
        stiva.pop();
        aux.push_back(a);

    }while(y!=a);
    sort(aux.begin(),aux.end());//sortez elementele componentei
    sol.push_back(aux);//adaug componenta la solutie
}
void dfs(int nod,int lvl)
{
    low[nod]=level[nod]=lvl;//completez nivelele
    stiva.push(nod);//adaug in stiva
    for(auto const &i:v[nod])//iau fiecare nod ce are lagatura cu elementul 'nod'
    {
        if(low[i]==0)//nu e completat nivelul
        {
            dfs(i,lvl+1);
            low[nod]=min(low[nod],low[i]);
            if(low[i]>=level[nod])//daca nivelul minim al lui i e mai mare decat nivelul curent al lui nod  inseamna ca am o componenta conexa
              Addcomponent(nod,i);
        }
        else
          low[nod]=min(low[nod],level[i]);//actualizez nivelul minim
    }
}
int main()
{
    int n,m,x,y;
    f>>n>>m;
    for(int i=1;i<=m;i++)//formez lista de adiacenta neorientata
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1,1);
    g<<sol.size()<<"\n";
    for(auto const &i:sol)
    {
        for(auto const &j:i)
          g<<j<<" ";
        g<<"\n";
    }
    return 0;
}