#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("biconex.in");
ofstream fout("biconex.out");
#define MAX 100010

typedef vector <int> :: iterator iter;
vector <int> G[MAX], comp;
vector <vector <int> > ans;

int viz[MAX], ad[MAX], de[MAX], dr;
pair<int, int> st[MAX];

void df(int nod, int dad)
{
    viz[nod] = 1;
    ad[nod] = ad[dad] + 1;
    de[nod] = ad[nod];
    for(iter it = G[nod].begin() ; it != G[nod].end() ; it++)
    {
        if(*it == dad)
            continue;
        if(!viz[*it])
        {
            st[++dr] = make_pair(nod, *it);
            df(*it, nod);
            de[nod] = min(de[nod], de[*it]);
            if(de[*it] >= ad[nod])
            {
                comp.clear();
                while(st[dr].first != nod || st[dr].second != *it)
                    comp.push_back(st[dr--].second);
                comp.push_back(*it);
                comp.push_back(nod);
                dr--;
                ans.push_back(comp);
            }
        }
        else
            de[nod] = min(de[nod], ad[*it]);
    }

}

int main()
{
    int n, m, x, y, i;
    fin >> n >> m;
    while(m--)
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i = 1 ; i <= n ; i++)
        if(!viz[i])
            df(i, 0);
    fout << ans.size() << "\n";
    for(vector <vector <int> > :: iterator it = ans.begin() ; it != ans.end() ; it++)
    {
        for(iter it1 = it->begin() ; it1 != it->end() ; it1++)
            fout << *it1 << " ";
        fout << "\n";
    }
}