#include <fstream>
#include <vector>
#include <stack>
#include <algorithm>
using namespace std;
ofstream fout("biconex.out");
ifstream fin("biconex.in");
const int NMAX = 100005;

int n, m, nr_sol;
int Min[NMAX], Viz[NMAX];
vector<int> Graf[NMAX], Sol[NMAX];
stack<int> s;

void citire()
{
    int x, y;

    fin >> n >> m;
    for(int i=1; i<=m; i++) {
        fin >> x >> y;
        Graf[y].push_back(x);
        Graf[x].push_back(y);
    }
}

void adauga(int x, int y)
{
    nr_sol++;
    while(s.top() != y) {                       // elimina din stiva pana ajungi la ultimele 2 noduri
         Sol[nr_sol].push_back(s.top());        // adauga la solutie elementele eliminate
         s.pop();
    }

    s.pop();                                    // scoate din stiva penultimul nod
    Sol[nr_sol].push_back(y);                   // adauga si ultimele 2 noduri
    Sol[nr_sol].push_back(x);

    sort(Sol[nr_sol].begin(), Sol[nr_sol].end());
}

void dfs(int nod, int tata)
{
    Min[nod] = Viz[nod] = Viz[tata] + 1;

    for(vector<int>::iterator it = Graf[nod].begin(); it != Graf[nod].end(); ++it) {
        if(*it == tata) continue;
        if(!Viz[*it]) {
            s.push(*it);
            dfs(*it, nod);
            Min[nod] = min(Min[nod], Min[*it]);
            if(Viz[nod] <= Min[*it])
                adauga(nod, *it);
        }
        else Min[nod] = min(Min[nod], Viz[*it]);
    }
}

void afis()
{
    fout << nr_sol << '\n';
    for(int i=1; i<=nr_sol; i++) {
        for(vector<int>::iterator it = Sol[i].begin(); it != Sol[i].end(); ++it)
            fout << *it << ' ';
        fout << '\n';
    }
}

int main()
{
    citire();
    dfs(1, 0);
    afis();
    return 0;
}