#include <bits/stdc++.h>
using namespace std;
using ll = long long;

ifstream fin("biconex.in");
ofstream fout("biconex.out");

int n, m, cnt;
vector<vector<int> > adj(100001);
vector<int> tin(100001), low(100001), viz(100001);
stack<pair<int, int> > s;
vector<set<int> > comp;

void solve(int x, int y){

    set<int> c;
    int a, b;

    do{
        a = s.top().first;
        b = s.top().second;
        s.pop();

        c.insert(a);
        c.insert(b);

    }while(a != x || b != y);

    comp.push_back(c);
}

void dfs(int nod, int p){

    tin[nod] = low[nod] = ++cnt;
    viz[nod] = 1;

    for(auto i : adj[nod]){

        if(i == p) continue;

        if(viz[i]){
            low[nod] = min(low[nod], tin[i]);
        }
        else{
            s.push({nod, i});
            dfs(i, nod);
            low[nod] = min(low[nod], low[i]);

            if(low[i] >= tin[nod]){
                solve(nod, i);
            }
        }
    }
}

int main(){

    fin >> n >> m;

    for(int i = 1; i <= m; i++){
        int a, b;
        fin >> a >> b;

        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    dfs(1, -1);

    fout << comp.size() << '\n';
    for(auto i : comp){
        for(auto j : i)
            fout << j << ' ';
        fout << '\n';
    }
}