#include <cstdio>
#include <vector>
#include <bitset>
#include <stack>

using namespace std;
const int NMAX = 100010;
vector <int> graf[NMAX];
vector< vector<int> > componente;
bitset <NMAX> viz;
stack <int> stiva;
int nivel[NMAX], inaltime_maxima[NMAX];
int n,m;

void read()
{
    freopen("biconex.in","r",stdin);
    freopen("biconex.out","w",stdout);
    scanf("%d %d",&n,&m);
    int x,y;
    for(int i = 0 ; i < m ; i++)
    {
        scanf("%d %d",&x,&y);
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
}

void AdaugaInSolutie(int nod , int tata)
{
    vector <int> solutie;
    solutie.push_back(tata);
    while(!stiva.empty() && stiva.top() != nod)
    {
        int nodnou = stiva.top();
        solutie.push_back(nodnou);
        stiva.pop();
    }
    solutie.push_back(nod);
    stiva.pop();
    componente.push_back(solutie);
}


void dfs(int nod , int tata)
{
    nivel[nod] = nivel[tata] + 1;
    inaltime_maxima[nod] = nivel[nod];
    viz[nod] = true;
    for(vector <int> :: iterator it = graf[nod].begin(); it != graf[nod].end(); it++)
    {
        if(*it == tata)
            continue;
        if(viz[*it] == false)
        {
            stiva.push(*it);
            dfs(*it,nod);
            nivel[*it] = min(inaltime_maxima[*it],inaltime_maxima[nod]);
            if(inaltime_maxima[*it] >= nivel[nod])
            {
                AdaugaInSolutie(*it,nod);
            }
        }
        else
        {
            inaltime_maxima[*it] = min(nivel[*it],inaltime_maxima[nod]);
        }
    }

}



void rezolvare()
{
    nivel[0] = -1;
    for(int i= 1 ; i<= n ;i++)
    {
        if(viz[i] == false)
        {
            dfs(i,0);
        }
    }
}


void afisare()
{
    printf("%d\n",componente.size());

    for(int i = 0 ; i < componente.size(); i++)
    {
        for( vector <int> :: iterator it = componente[i].begin(); it!= componente[i].end() ; it++)
            printf("%d ",*it);
        printf(" nr de elemente %d \n",componente[i].size());
    }
}

int main()
{
    read();
    rezolvare();
    afisare();
    return 0;
}