#include <bits/stdc++.h>

using namespace std;
ifstream f("biconex.in");
ofstream g("biconex.out");

const int NMax = 100003;

int n,m,x,y,biconex;
int viz[NMax],low[NMax];
vector<int> G[NMax],c[NMax];
stack<int> s;

void dfs(int nod,int tata){
    viz[nod] = viz[tata] + 1;

    low[nod] = viz[nod];

    s.push(nod);

    for(int i = 0; i < G[nod].size(); ++i){
        if(!viz[G[nod][i]]){
            dfs(G[nod][i], nod);

            low[nod] = min(low[nod],low[G[nod][i]]);

            if(low[G[nod][i]] >= viz[nod]){
                biconex++;
                while(s.top() != G[nod][i]){
                    c[biconex].push_back(s.top());
                    s.pop();
                }
                c[biconex].push_back(G[nod][i]);
                c[biconex].push_back(nod);
                s.pop();
            }

        }else
            low[nod] = min(low[nod],viz[G[nod][i]]);
    }
}
int main()
{
    f >> n >> m;
    for(int i = 1; i <= m; ++i){
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    dfs(1,0);
    g << biconex << '\n';
    for(int i = 1; i <= biconex; ++i){
        for(int j = 0; j < c[i].size(); ++j)
            g << c[i][j] << ' ';
        g << '\n';
    }
    return 0;
}