#include<iostream>
#include<fstream>
#include<vector>
#include<queue>
#include<cmath>
#include<stack>
#include<bitset>

using namespace std;

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

int const NMax = 100005;
int lv[NMax], low[NMax];
bitset <NMax> use;
vector <int> G[NMax], CBC[NMax];
stack <pair <int, int> > S;
int n, m, cbc;

void Read()
{
    int i, x, y;

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

void DFS(int nod, int tata)
{
    vector <int>::iterator it;
    use[nod] = 1;
    lv[nod] = lv[tata] + 1;
    low[nod] = lv[nod];

    for(it = G[nod].begin(); it != G[nod].end(); it++){
        if(use[*it])
            low[nod] = min(low[nod], lv[*it]);

        if(!use[*it]){
            S.push(make_pair(nod, *it));
            DFS(*it, nod);
            low[nod] = min(low[nod], low[*it]);

            if(low[*it] >= lv[nod]){
                cbc++;
                while(S.top().first != nod && S.top().second != (*it)){
                    CBC[cbc].push_back(S.top().second);
                    S.pop();
                }
                CBC[cbc].push_back(*it);
                CBC[cbc].push_back(nod);
                S.pop();
            }
        }
    }
}

void Print()
{
    int i;
    vector <int>::iterator it;

    g<<cbc<<"\n";
    for(i=1; i<=cbc; i++){
        for(it = CBC[i].begin(); it != CBC[i].end(); it++)
            g<<(*it)<<" ";
        g<<"\n";
    }
}

int main()
{
    Read();
    DFS(1, 0);
    Print();
    return 0;
}