#include <fstream>
#include <vector>
#include <algorithm>
#include <climits>
#define nmax 100005
#include <stack>
using namespace std;
vector <unsigned int> a[nmax];
vector <unsigned int> v[nmax];
unsigned int ll[nmax],niv[nmax],t[nmax];
stack < pair<unsigned int,unsigned int> > st;
bool viz[nmax];
unsigned int cost[nmax],n,k,nrm=INT_MAX,nr;
void tar(unsigned int x)
{
    ll[x]=niv[x]=niv[t[x]]+1;
    viz[x]=1;
    unsigned int i,y;
    pair<unsigned int,unsigned int> e;
    for (i=0;i<a[x].size();i++)
    {
        y=a[x][i];
        if (y!=t[x])
        {
            if (!niv[y])
            {
                t[y]=x;
                st.push(make_pair(x,y));
                tar(y);
                ll[x]=min(ll[x],ll[y]);
                if (ll[y]>=niv[x])
                {
                    nr++;
                    do
                    {
                        e=st.top();
                        v[nr].push_back(e.second);
                        st.pop();
                    }
                    while (e.first!=x);
                    v[nr].push_back(e.first);
                }
            }
            else
            {
                if (viz[y])
                    ll[x]=min(ll[x],niv[y]);
            }
        }
    }
}
int main()
{
    ifstream f("biconex.in");
    ofstream g("biconex.out");
    unsigned int m,i,x,y,j;
    f>>n>>m;
    for (i=1;i<=m;i++)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    tar(1);
    g<<nr<<'\n';
    for (i=1;i<=nr;i++)
    {
        for (j=0;j<v[i].size();j++)
            g<<v[i][j]<<' ';
        g<<'\n';
    }
    f.close();
    g.close();
    return 0;
}