#include <bits/stdc++.h>

using namespace std;
const int N = 1e5 + 5;
vector <int> g[N];
int id[N], low[N], st[N], k, timer;
vector <vector <int>> bcc;
void dfs(int u, int p)
{
    low[u] = id[u] = id[p] + 1;
    st[k++] = u;
    for(int v : g[u]) {
        if(!id[v]) {
            dfs(v, u);
            low[u] = min(low[u], low[v]);
            if(low[v] == id[u]) {
                bcc.push_back({u, v});
                while(st[--k] != v)
                    bcc.back().push_back(st[k]);
            }
        } else low[u] = min(low[u], id[v]);
    }

}

int main()
{
    ifstream cin("biconex.in");
    ofstream cout("biconex.out");
    int n, m;
    cin >> n >> m;
    for(int i = 0, u, v; i < m; i++)
        cin >> u >> v,
        g[u].push_back(v),
        g[v].push_back(u);
    for(int i = 1; i <= n; i++) if(!id[i])
        dfs(i, 0);
    cout << bcc.size() << "\n";
    for(auto& comp : bcc) {
        for(int x : comp)
            cout << x << " ";
        cout << "\n";
    }
    return 0;
}