#include <bits/stdc++.h>
using namespace std;

const int N = 1e5 + 5;

vector<int> g[N], articulatie;
vector< vector<int> > comp;
vector< pair<int, int> > critice;
stack<int> st;
int n, m;

ifstream in("biconex.in");
ofstream out("biconex.out");

void citire()
{
    in>>n>>m;
    for ( int i = 1 ; i <= m ; i++ )
    {
        int x, y;
        in>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

int viz[N], low[N], niv[N];

void adauga_comp(int x, int adaug)
{
    vector<int> aux;
    while ( st.top() != x )
    {
        aux.push_back(st.top());
        st.pop();
    }
    aux.push_back(x);
    st.pop();
    aux.push_back(adaug);
    comp.push_back(aux);
}

bool rad = true;

void dfs(int nod, int tata)
{
    viz[nod] = 1;
    niv[nod] = niv[tata] + 1;
    low[nod] = niv[nod];
    st.push(nod);
    for ( int vec : g[nod] )
    {
        if ( vec == tata )
            continue;
        if ( viz[vec] )
        {
            if ( vec == 1 )
            {
                rad = false;
            }
            low[nod] = min(low[nod], niv[vec]);
        }
        else
        {
            dfs(vec, nod);
            low[nod] = min(low[nod], low[vec]);
            if ( niv[nod] <= low[vec] )
            {
                adauga_comp(vec, nod);
            }
        }
    }
}
void rez()
{
    dfs(1, 0);
    out<<comp.size()<<'\n';
    for ( int i = 0 ; i < comp.size() ; i++ )
    {
        for ( int j : comp[i] )
        {
            out<<j<<" ";
        }
        out<<'\n';
    }
}
int main()
{
    citire();
    rez();
    return 0;
}