#include <cstdio>
#include <vector>
#include <bitset>
#include <stack>
#define Nmax 100010
using namespace std;
vector <int > G[Nmax];
bitset <Nmax> viz;
stack  <int> stiva;
vector < vector < int > > solutie;
int  niv[Nmax],inalt_max[Nmax];
int n,m,nr;

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);
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void formare(int x , int tata)
{
    vector <int> aux ;
    aux.push_back(tata);
    while( !stiva.empty() && stiva.top() != x)
    {
        int stop = stiva.top();
        aux.push_back(stop);
        stiva.pop();
    }
    aux.push_back(x);
    stiva.pop();
    solutie.push_back(aux);
}

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

void dfs(int x , int t)
{
    viz[x] = true;
    niv[x] = niv[t]+1;
    inalt_max[x] = niv[x];
    vector <int> :: iterator it;
    for( it = G[x].begin(); it != G[x].end() ; it++)
    {
        if(*it == t)
            continue;
        if(viz[*it] == false)
        {
            stiva.push(*it);
            dfs(*it,x);
            inalt_max[x] = min(inalt_max[*it],inalt_max[x]);
            if(inalt_max[*it] >= niv[x])
            {
                formare(*it,x);
                nr++;
            }
        }
        else
        {
            inalt_max[x] = min(niv[*it],inalt_max[x]);
        }
    }
}

int main()
{
    read();
    niv[0] = -1;
    for(int i =  1 ; i <= n ; i++)
    {
        if(viz[i] == false)
            dfs(i,0);
    }
    printf("%d\n",nr);
    afisare();
    return 0;
}