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

const int nmx = 100005;

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

inline void citire() {
    int m, y, x;
    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 adauga(int a, int b){
    ++ t;
    while(S.top() != b){
        R[t].push_back(S.top());
        S.pop();
    }
    S.pop();
    R[t].push_back(a);
    R[t].push_back(b);
    sort(R[t].begin(), R[t].end());
}

void dfs(int nod, int tata){
    niv[nod] = 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);
            dfs(*it, nod);
            Min[nod] = min(Min[nod], Min[*it]);
            if(niv[nod] <= Min[*it])
                adauga(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);
            dfs(i, 0);
            S.pop();
        }
    afish();
    return 0;
}