#include <cstdio>
#include <vector>

using namespace std;

const int nmx = 100002;

int n,m;
int grad[nmx],tati[nmx];
vector <int> g[nmx], aux, st;
vector <vector<int> > ras;

void citire()
{
    scanf("%d %d", &n, &m);
    for(int i = 1; i <= m; ++i)
    {
        int nod1,nod2;
        scanf("%d %d", &nod1, &nod2);
        g[nod1].push_back(nod2);
        g[nod2].push_back(nod1);
    }
}

void afish(int tata, int nod)
{
    aux.clear();

    while(st.back() != nod)
    {
        aux.push_back(st.back());
        st.pop_back();
    }

    st.pop_back();
    aux.push_back(nod);
    aux.push_back(tata);

    ras.push_back(aux);
}

void dfs(int tata, int nod)
{
    tati[nod] = grad[nod] = grad[tata] + 1;

    for(vector<int>::iterator it = g[nod].begin(); it != g[nod].end(); ++it)
    {
        if(*it == tata)
            continue;

        if(not grad[*it])
        {
            st.push_back(*it);
            dfs(nod,*it);
            tati[nod] = min(tati[nod],tati[*it]);
            if(tati[*it] >= grad[nod])
                afish(nod,*it);
        }
        else
        {
            tati[nod] = min(tati[nod],grad[*it]);
        }
    }
}

void rezolvare()
{
    for(int i = 1; i <= n; ++i)
        if(not grad[i])
        {
            st.push_back(i);
            dfs(0,i);
            st.pop_back();
        }
}

void afish()
{
    printf("%d\n", ras.size());

    for(size_t i = 0; i < ras.size(); ++i)
    {
        for(size_t j = 0; j < ras[i].size(); ++j)
            printf("%d ", ras[i][j]);
        printf("\n");
    }
}

int main()
{
    freopen("biconex.in", "r", stdin);
    freopen("biconex.out", "w", stdout);
    citire();
    rezolvare();
    afish();
    return 0;
}