//#include <iostream>
#include <bits/stdc++.h>
using namespace std;
ifstream in("biconex.in");
ofstream out("biconex.out");
const int Max=100005; int n,m;
vector <int >v[Max],comp[Max]; stack <int>s;
bool viz[Max]; int nivel[Max],nma[Max],nr;
void citire()
{
    in>>n>>m; int x,y;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void dfs(int nod,int tata=0)
{
    viz[nod]=1; s.push(nod); nivel[nod]=nivel[tata]+1;
    nma[nod]=nivel[nod];
    for(int j=0;j<v[nod].size();j++)
    {
        int vecin=v[nod][j];
        if(tata!=vecin)
        {
            if(viz[vecin])
            {
                if(nivel[vecin]<nma[nod])
                    nma[nod]=nivel[vecin];
            }
            else
            {
                dfs(vecin,nod);
                if(nma[nod]>nma[vecin])
                    nma[nod]=nma[vecin];
                if(nivel[nod]<=nma[vecin])
                {
                     nr++;
                    while(s.top()!=vecin)
                    {
                       comp[nr].push_back(s.top());
                       s.pop();
                    }
                     s.pop();
                     comp[nr].push_back(vecin); comp[nr].push_back(nod);
                }
            }
        }
    }
}


int main()
{
    citire(); dfs(1);
    out<<nr<<"\n";
    for(int i=1;i<=n;i++)
    {
        for(int j=0;j<comp[i].size();j++)
            out<<comp[i][j]<<" ";
            out<<"\n";

    }
    return 0;
}