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

const int nmx = 100005;

int n;
int niv[nmx], Min[nmx];
vector <int> G[nmx];
vector <int> R[nmx];
int t;
stack <int> S;

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

inline void afish(int a, int b){
    ///nu scoti b
    ++ t;
    while(S.top() != b){
        R[t].push_back(S.top());
        S.pop();
    }
    S.pop();
    R[t].push_back(b);
    R[t].push_back(a);
    sort(R[t].begin(), R[t].end());
}

void bfs(int nod, int tata){
    niv[nod] = niv[tata] + 1;
    Min[nod] = niv[tata] + 1;
    for(vector<int>::iterator it = G[nod].begin(); it != G[nod].end(); ++it){
        if(*it == tata)
            continue;
        if(not niv[*it]){
            S.push(*it);
            bfs(*it, nod);
            Min[nod] = min(Min[nod], Min[*it]);
            if(niv[nod] <= Min[*it])
                afish(nod, *it);
        }
        else
            Min[nod] = min(Min[nod], niv[*it]);
    }
}

inline void afish(){
    printf("%d\n", t);
    for(int i = 1; i <= t; ++i){
        for(vector<int>::iterator it = R[i].begin(); it != R[i].end(); ++it)
            printf("%d ", *it);
        printf("\n");
    }
}

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

    citire();

    for(int i = 1; i <= n; ++i)
        if(not niv[i]){
            S.push(i);
            bfs(1,0);
            S.pop();
        }

    afish();

    return 0;
}