//#include <iostream>
#include <bits/stdc++.h>
using namespace std;
ifstream in("biconex.in");
ofstream out("biconex.out");
const int Max=100005;
int n,m,nr;
vector <int>v[Max],comp[Max];
stack <int>s; bool viz[Max]; int nivel[Max],nma[Max];
void citire()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y; in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
void dfs(int nod,int tata=0)
{
     viz[nod]=1; nivel[nod]=nma[nod]=nivel[tata]+1;
     s.push(nod);
     for(int j=0;j<v[nod].size();j++)
     {
         int vecin=v[nod][j];
         if(!viz[vecin])
         {
             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();
                 }
                 comp[nr].push_back(vecin);
                 comp[nr].push_back(nod);
                 s.pop();
             }
         }
         else if(nma[nod]>nivel[vecin])
            nma[nod]=nivel[vecin];
     }
}
int main()
{
    citire();
    dfs(1);
    out<<nr<<"\n";
    for(int i=1;i<=nr;i++)
    {
        for(int j=0;j<comp[i].size();j++)
            out<<comp[i][j]<<" ";
        out<<"\n";
    }
    return 0;
}