#include <cstdio>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <stack>
using namespace std;

const int nmax = 100010;

int n, m, x, y, level[nmax], low[nmax];
vector<int> g[nmax];
vector<vector<int> > bc;
bool used[nmax];
stack<pair<int, int> > s;

void get_comp(int x, int y)
{
    vector<int> comp;
    pair<int, int> now;
    do {
        now = s.top();
        s.pop();
        comp.push_back(now.second);
    }while (!s.empty() && now.first != x);
    comp.push_back(x);
    bc.push_back(comp);
}

void dfs(int node, int father = 0)
{
    used[node] = 1;
    low[node] = level[node];

    for (int vec : g[node])
    {
        if (vec == father) continue;
        if (!used[vec])
        {
            level[vec] = level[node] + 1;
            s.push(make_pair(node, vec));
            dfs(vec, node);
            low[node] = min(low[node], low[vec]);
            if (level[node] <= low[vec])
               get_comp(node, vec);
        }else
            low[node] = min(low[node], level[vec]);
    }
}

int main()
{
    freopen("biconex.in", "r", stdin);
    freopen("biconex.out", "w", stdout);

    //freopen("in", "r", stdin);

    scanf("%i %i", &n, &m);
    for (int i = 1; i <= m; ++ i)
    {
        scanf("%i %i", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }

    for (int i = 1; i <= n; ++ i)
        if (!used[i])
        {
            level[i] = 1;
            dfs(i);
        }

    printf("%i\n", bc.size());
    for (int i = 0; i < bc.size(); ++ i, printf("\n"))
        for (int j = 0; j < bc[i].size(); ++ j)
            printf("%d ", bc[i][j]);
}