#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define vii vector < pii >
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class P , class Q > ostream& operator<<(ostream& stream, pair < P , Q > v){ stream << "(" << v.fi << ',' << v.se << ")"; return stream;}
template < class T > ostream& operator<<(ostream& stream, const vector<T> v){ stream << "[ "; for (int i=0; i<(int)v.size(); i++) stream << v[i] << " "; stream << "]"; return stream;}
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
const int N = 1e5 + 5;
int low[N];
int fup[N];
int was[N];
vi g[N];
vector < pii > v;
vector < vi > answer;
int timer = 0;
void Go(int x,int y) {
    set < int > ss;
    while (1) {
        auto tp = v.back();
        ss.insert(tp.fi);
        ss.insert(tp.se);
        v.pop_back();
        if (tp == mp(x,y))
            break;
    }
    answer.pb(vi(all(ss)));
}
void dfs(int node = 1,int prev = -1) {
    was[node] = 1;
    low[node] = fup[node] = ++timer;
    for (auto it : g[node]) {
        if (it == prev)
            continue;
        if (!was[it]) {
            v.pb(mp(it,node));
            dfs(it,node);
            smin(fup[node],fup[it]);
            if (fup[it] >= low[node]) {
                Go(it,node);
            }
        } else {
            smin(fup[node],low[it]);
        }
    }
}
int main(void) {
    ifstream cin("biconex.in");
    ofstream cout("biconex.out");
    int n,m;
    cin>>n>>m;
    while (m --) {
        int u,v;
        cin>>u>>v;
        g[u].pb(v);
        g[v].pb(u);
    }
    for (int i = 1;i <= n;++i)
        if (!was[i]) {
            dfs(i);
        }
    cout << (answer.size()) << '\n';
    for (auto V : answer) {
        for (int i = 0;i < V.size();++i)
            cout << V[i] << " \n"[i + 1 == V.size()];
    }
    return 0;
}