#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <stack>

using namespace std;

ifstream in("ctc.in");
ofstream out("ctc.out");

const int nmax = 15;

class Graf
{
private:
    bool orientat;
    int nrNoduri;
    vector <int> listaAdiacenta[nmax];
public:
    Graf(int nrNoduri = 0, bool orientat = false);
    int get_nrNoduri();
    void citireMuchii(int nrMuchii);
    vector<int> BFS(int start);
    void DFS(int nodCurent, bool *vizitatDFS);
    int nrComponenteConexe();
    void DFSStiva(int nodcurent, bool *vizitatDFS, stack<int> &stivaTimp);
    void sortareTopologica();
    void Tarjan(int &timpCurent, int nodCurent, int *timpDescoperire, int *minimLegat, bool *estePeStiva, stack <int> &stiva, vector<vector<int>> &componenteTConexe);
    void CTCabc();
};

Graf :: Graf(int nrNoduri, bool orientat) : nrNoduri(nrNoduri), orientat(orientat)
{
    this->nrNoduri = nrNoduri;
    this->orientat = orientat;
}

int Graf::get_nrNoduri()
{
    return this->nrNoduri;
}

void Graf::citireMuchii(int nrMuchii)
{
    int nod1, nod2;
    for(int i = 0; i < nrMuchii; i++)
    {
        in >> nod1 >> nod2;
        listaAdiacenta[nod1].push_back(nod2);
        if(!orientat)
        {
            listaAdiacenta[nod2].push_back(nod1);
        }
    }
}

void Graf::Tarjan(int &timpCurent, int nodCurent, int *timpDescoperire, int *minimLegat, bool *estePeStiva, stack <int> &stiva, vector<vector<int>> &componenteTConexe)
{
    stiva.push(nodCurent);
    estePeStiva[nodCurent] = true;
    timpDescoperire[nodCurent] = timpCurent;
    minimLegat[nodCurent] = timpCurent;
    timpCurent++;
    for(auto vecin:listaAdiacenta[nodCurent])
    {
        if(timpDescoperire[vecin] == 0)
        {
            Tarjan(timpCurent, vecin, timpDescoperire, minimLegat, estePeStiva, stiva,componenteTConexe);
            minimLegat[nodCurent] = min(minimLegat[nodCurent], minimLegat[vecin]);
        }
        else if(estePeStiva[vecin])
        {
            minimLegat[nodCurent] = min(minimLegat[nodCurent], minimLegat[vecin]);
        }
    }
    if(timpDescoperire[nodCurent] == minimLegat[nodCurent])
    {
        vector <int> componentaCurenta;
        while(stiva.top() != nodCurent)
        {
            componentaCurenta.push_back(stiva.top());
            estePeStiva[stiva.top()] = false;
            stiva.pop();
        }
        componentaCurenta.push_back(stiva.top());
        estePeStiva[stiva.top()] = false;
        stiva.pop();
        componenteTConexe.push_back(componentaCurenta);
    }
}

void Graf::CTCabc()
{
    int timpCurent = 1;
    int timpDescoperire[nmax] = {0}, minimLegat[nmax] = {0};
    bool estePeStiva[nmax] = {false};
    stack <int> stiva;
    vector <vector <int>> componenteTConexe;
    for(int i = 1; i <= nrNoduri; i++)
    {
        if(timpDescoperire[i] == 0)
        {
            Tarjan(timpCurent, i, timpDescoperire, minimLegat, estePeStiva, stiva, componenteTConexe);
        }
    }
    out << componenteTConexe.size() << "\n";
    for(auto x:componenteTConexe)
    {
        for(auto y:x)
        {
            out << y << " ";
        }
        out << "\n";
    }
}

int main() {
    int n, m;
    in >> n >> m;
    Graf g(n,true);
    g.citireMuchii(m);
    g.CTCabc();
    return 0;
}