#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

#define lim 100010
int n,m;
int viz[lim], up[lim], lvl[lim];
vector <int> G[lim];
vector <vector <int>> sol;
vector <pair <int, int>> st;


void dfs (int nod, int dad)
{
    viz[nod] = 1;
    lvl[nod] = lvl[dad] + 1;
    up[nod] = lvl[nod];
    for (auto it:G[nod])
        if (!viz[it])
        {
            st.push_back ({it, nod});
            dfs (it, nod);
            up[nod] = min (up[nod], up[it]);
            if (up[it] >= lvl[nod])
            {
                vector <int> aux;
                while (st.back() != make_pair(it,nod) && !st.empty())
                {
                    aux.push_back(st.back().first);
                    st.pop_back();
                }
                st.pop_back();
                aux.push_back(nod);
                aux.push_back(it);
                sol.push_back(aux);
            }
        }
        else
            up[nod] = min (up[nod], lvl[it]);
}


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

    for (int i=1; i<=n; i++)
        if (!viz[i])
            dfs (i, 0);

    fout<<sol.size()<<'\n';
    for (auto it:sol)
    {
        for (auto itt:it)
            fout<<itt<<' ';
        fout<<'\n';
    }

    fout.close();
    return 0;
}