#include <iostream>
#include<vector>
#include<fstream>
#include<deque>
#include<list>
using namespace std;
int n,m;
pair <int, int> ms[100001];
vector< vector<int> > graph;
vector<int> gr[100001];
vector<bool> visited;
int nm;
void dfs(int vertex)
{
    if(vertex<0||vertex>n-1)
        return;
    vector<int> s;
    int element;
    unsigned int i;
    bool found;
    s.push_back(vertex);
    visited[vertex]=true;
    while(!s.empty())
    {
        element=s.back();
        found=false;
        for(i=0;i<graph[element].size()&&!found;i++)
        {
            if(!visited[graph[element][i]])
            {
                found=true;
            }
        }
        if(found)
        {
            i--;
            ms[nm++]=make_pair(element,graph[element][i]);
            s.push_back(graph[element][i]);
            visited[graph[element][i]]=true;

        }
        else
        {
            s.pop_back();
        }
    }
}
int main()
{
    ifstream f("biconex.in");
    ofstream g("biconex.out");
    int nr;
    f>>n>>m;
    graph.resize(n);
    visited.resize(n,false);
    int x,y;
    for(int i=0;i<n;i++)
    {
        gr[i].resize(n,0);
    }
    for(int i=0;i<m;i++)
    {
        f>>x>>y;
        x--;
        y--;
        graph[x].push_back(y);
        graph[y].push_back(x);
        gr[x][y]=1;
        gr[y][x]=1;
    }
    for(int i=0;i<visited.size()&&i<n;i++)
    {
        if(!visited[i])
        {
            dfs(i);
        }
    }
    nr=0;
    int k=nm-1;
    vector <list <int> > R;
    for(int i=nm-1;i>=0;i--)
    {
        bool found=false;
        list <int> rez;
        rez.push_front(ms[i].second+1);
        rez.push_front(ms[i].first+1);
        for( int j=i-1;j>=0&&found==false;j--)
        {
            if(gr[ms[i].second][ms[j].first]==1&&ms[i].first!=ms[j].first)
            {found=true;
            for(int k=j;k<i;k++)
                 rez.push_front(ms[k].first+1);
            i=j;
            }
        }
        R.push_back(rez);
        rez.clear();
        nr++;
    }
    g<<nr<<endl;
    for(size_t i=0;i<R.size();i++)
    {
        while(!R[i].empty())
        {
            g<<R[i].front()<<" ";
            R[i].pop_front();
        }
        g<<endl;
    }
    f.close();
    g.close();
    return 0;
}