#include <bits/stdc++.h>

using namespace std;

ifstream fin("biconex.in");
ofstream fout("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 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() {
    fin >> n >> m;
    for(int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1);
    fout << nr << "\n";
    for(int i = 1; i <= nr; i++) {
        for(int j = 0; j < comp[i].size(); j++)
            fout << comp[i][j] << " ";
        fout << "\n";
    }
    return 0;
}