#include <fstream>
#include <vector>
#include <bitset>
#include <queue>
#include <algorithm>
#include <utility>
#include <string.h>
#include <set>
#include <stack>

using namespace std;

ifstream cin("biconex.in");
ofstream cout("biconex.out");

const int MAXN = 100005;
const int oo = (1<<31)-1;

typedef vector<int> Graph[MAXN];
typedef vector<int> :: iterator It;

Graph G;
int N, M, Level[MAXN], LowLink[MAXN];
stack< pair<int, int> > Stack;
vector <set <int> > Bcon;

const inline void Get_min(int &a, const int b) {
    if( a>b )
        a = b;
}

inline void ReadInput() {
    cin >> N >> M;
    for(int i = 1 ; i <= M ; ++ i){
        int x, y;
        cin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

inline void CatchBc(int X, int Y) {
    int Tx, Ty;
    set <int> actB;
    do {
        Tx = Stack.top().first;
        Ty = Stack.top().second;
        Stack.pop();
        actB.insert(Tx);
        actB.insert(Ty);
    } while(Tx != X || Ty != Y);
    Bcon.push_back(actB);
}

inline void DFs(int Node, int Father, int actLevel) {
    Level[Node] = LowLink[Node] = actLevel;
    for(It it = G[Node].begin(), fin = G[Node].end(); it != fin ; ++ it) {
        if(*it == Father)
            continue;
        if(!Level[*it]) {
            Stack.push(make_pair(Node, *it));
            DFs(*it, Node, actLevel + 1);
            Get_min(LowLink[Node], LowLink[*it]);
            if(LowLink[*it] >= Level[Node])
                CatchBc(Node, *it);
        }
        else Get_min(LowLink[Node], LowLink[*it]);
    }
}

inline void WriteBiconex() {
    cout << Bcon.size() << "\n";
    for(int i = 0 ; i < Bcon.size() ; ++ i, cout << "\n")
        for(set<int> :: iterator it = Bcon[i].begin(), fin = Bcon[i].end() ; it != fin ; ++ it)
            cout << *it << " ";
}

int main() {
    ReadInput();
    DFs(1, 0, 0);
    WriteBiconex();
    cin.close();
    cout.close();
    return 0;
}