#include <bits/stdc++.h>
using namespace std;
string out[2]{ "No", "Yes" };
ifstream fin("biconex.in");
ofstream fout("biconex.out");
const char sp = ' ';
const char nl = '\n';
const int inf = 1e9;
const int mod = 1e9 + 7;
#define all(x) x.begin(), x.end()

int n, m;
const int nmax = 1e5;
vector<int> g[nmax + 1];
vector<vector<int>> components;
int viz[nmax + 1]{0}, tin[nmax + 1]{0}, low[nmax + 1]{0};
int timer = 0;
stack<int> st;

void dfs(int v, int p = -1) {
    viz[v] = 1;
    tin[v] = low[v] = ++timer;
    st.push(v);
    for (auto& u : g[v]) {
        if (u == p) {
            continue;
        }
        // back edge
        if (viz[u]) {
            low[v] = min(low[v], tin[u]);
        }
        else {
            dfs(u, v);
            low[v] = min(low[v], low[u]);
            if (low[u] >= tin[v]) {
                components.push_back({});
                while (st.top() != u) {
                    components.back().push_back(st.top());
                    st.pop();
                }
                components.back().push_back(u);
                components.back().push_back(v);
                st.pop();
            }
        }
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    fin >> n >> m;
    for (int i = 0; i < m; ++i) {
        int u, v;
        fin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    for (int i = 1; i <= n; ++i) {
        if (!viz[i]) {
            dfs(i);
        }
    }
    fout << components.size() << nl;
    for (auto& c : components) {
        for (auto& x : c) {
            fout << x << sp;
        }
        fout << nl;
    }
}