#include <fstream>
#include <set>
#include <vector>
using namespace std;
ifstream cin ("biconex.in");
ofstream cout ("biconex.out");
bool u[100005];
vector<int> g[100005];
vector < set<int> > componente;
int lvl[100005];
int nma[100005];
int st[200005];
int vf;
int n,m;
void dfs(int nod,int tata)
{
    st[++vf] = nod;
    u[nod] = true;
    lvl[nod] = lvl[tata] + 1;
    nma[nod] = lvl[nod];
    for(auto urm:g[nod])
    {
        if(urm == tata)
            continue;
        if(u[urm])
        {
            nma[nod] = min(nma[nod],lvl[urm]);
            continue;
        }
        dfs(urm,vf);
        nma[nod] = min(nma[nod],nma[urm]);
        if(lvl[nod]<=nma[urm])
        {
            set<int> nou;
            while(st[vf]!=urm)
            {
                nou.insert(st[vf]);
                vf--;
            }
            nou.insert(st[vf]);
            vf--;
            nou.insert(nod);
            componente.push_back(nou);
        }
    }
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(u[i])
            continue;
        dfs(i,0);
    }
    cout << componente.size() << '\n';
    for(auto x:componente)
    {
        for(auto y:x)
            cout<< y << ' ';
        cout<<'\n';
    }
    return 0;
}