#include <iostream>
#include <cstdio>
#include <vector>
#include <stack>
#include <bitset>

using namespace std;

const int NMax = 100005;
vector < int > G[NMax], rez[NMax];
stack < pair < int, int > > st;
bitset < NMax > viz;
int tmp = 1, tov[NMax], low[NMax];
int bico;
int N, M;

void Solve(int nod)
{
    int nr = bico;
    while(!st.empty() && st.top().second != nod)
    {
        rez[nr].push_back(st.top().second);
        st.pop();
    }

    rez[nr].push_back(st.top().second);
    rez[nr].push_back(st.top().first);
    st.pop();
}

void DFS(int nod, int dad)
{
    viz[nod] = 1;
    low[nod] = tov[nod] = tmp;
    ++tmp;

    for(auto it: G[nod])
    {
        if(it==dad)
            continue;

        else
            if(!viz[it])
        {
            st.push({nod,it});
            DFS(it,nod);
            low[nod] = min(low[nod], low[it]);
            if(low[it] >= tov[nod])
            {
                ++bico;
                Solve(it);
            }
        }

        else
        {
            low[nod] = min(low[nod], tov[it]);
        }
    }
}

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

    scanf("%d%d",&N,&M);
    for(int i=1; i<=M; ++i)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for(int i=1; i<=N; ++i)
    {
        if(!viz[i])
            DFS(i,0);
    }

    cout << bico << "\n";

    for(int i=1; i<=bico; ++i)
    {
        for(auto it: rez[i])
            cout << it << " ";

        cout << "\n";
    }

    return 0;
}