#include <fstream>
#include <vector>
#include <stack>
using namespace std;

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

#define NMAX 100005

vector<int> G[NMAX];
vector<int> CBC[NMAX];
bool viz[NMAX];
int nivel[NMAX];
int nma[NMAX];
int nr;

stack<int> S;

void dfs(int nod, int parinte) {
    viz[nod] = 1;
    nivel[nod] = nivel[parinte] + 1;
    nma[nod] = nivel[nod];
    S.push(nod);

    for (auto it : G[nod]) {
        if (it != parinte) {
            if (viz[it]) {
                if (nma[nod] > nivel[it]) {
                    nma[nod] = nivel[it];
                }
            } else {
                dfs(it, nod);

                if (nma[nod] > nma[it]) {
                    nma[nod] = nma[it];
                }

                if (nivel[nod] <= nma[it]) {
                    while (S.size() && S.top() != it) {
                        CBC[nr].push_back(S.top());
                        S.pop();
                    }
                    CBC[nr].push_back(it);
                    S.pop();
                    CBC[nr].push_back(nod);
                    nr++;
                }
            }
        }
    }
}

int main() {
    int n, m;
    fin >> n >> m;
    while (m--) {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    dfs(1, 0);

    fout << nr << '\n';
    for (int i = 0; i < nr; ++i) {
        for (auto it : CBC[i]) {
            fout << it << ' ';
        }
        fout << '\n';
    }
    return 0;
}