#include <algorithm>
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <stack>
#include <utility>
#include <vector>
using namespace std;

const size_t MAXN = 100010;
ifstream fin ("biconex.in");
ofstream fout ("biconex.out");

int N, idx, dfsIdx[MAXN], lowIdx[MAXN];
vector <int> G[MAXN];
vector <vector <int>> bc;
stack <pair <int, int>> eSt;

void DFS (int v, int parent)
{
	dfsIdx[v] = lowIdx[v] = ++idx;

	for (auto &n : G[v])
		if (n == parent) continue;
		else if (!dfsIdx[n])
		{
			eSt.push (make_pair (v, n));
			DFS (n, v);
			lowIdx[v] = min (lowIdx[v], lowIdx[n]);

			if (lowIdx[n] >= dfsIdx[v])
			{
				int x, y;
				bc.push_back (vector <int>());
				do {
					x = eSt.top().first;
					y = eSt.top().second;
					eSt.pop();
                    bc.back().push_back (y);
                } while (x != v && y != n);
				bc.back().push_back (v);
			}
		}
		else lowIdx[v] = min (lowIdx[v], lowIdx[n]);
}

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

	for (size_t v = 1; v <= N; ++v)
		if (!dfsIdx[v])
			DFS (v, 0);

	fout << bc.size() << '\n';
	for (auto &biconex : bc)
	{
		for (auto &v : biconex)
			fout << v << ' ';
		fout << '\n';
	}

	return EXIT_SUCCESS;
}