#include <cstdio>
#include <cstdlib>
#include <vector>
#include <stack>
#include <algorithm>
using namespace std;


#define nmax 100110
#define pb push_back
#define mp make_pair
#define from first
#define to second


int niv[nmax], low[nmax], N, M, X, Y;
vector<int> G[nmax], newComp;
vector<vector<int> > C;
stack<pair<int, int> > edges;

void Comp(int X, int Y)
{
     newComp.clear();
     pair<int, int> p;
     do
     {
                  p = edges.top();
                  edges.pop();
                  newComp.pb(p.to);
     }while(p.from != X && p.to != Y);
     newComp.pb(p.from);
     C.pb(newComp);
}

void DFS(int node, int t = 0)
{
     low[node] = niv[node];
     vector<int> :: iterator it;
     for(it = G[node].begin(); it != G[node].end(); ++it)
     {
            if(*it == t) continue;
            if(!niv[*it])
            {
                         edges.push(mp(node, *it));
                         niv[*it] = niv[node] + 1;
                         DFS(*it, node);
                         low[node] = min(low[node], low[*it]);
                         if(low[*it] >= niv[node]) Comp(node, *it);
            }else
            {
                 low[node] = min(low[node], low[*it]);
            }
     }
}

int main()
{
    freopen("biconex.in", "r", stdin);
    freopen("biconex.out", "w", stdout);
    int i, j;
    scanf("%i %i", &N, &M);
    for(i = 1; i <= M; i++)
    {
          scanf("%i %i", &X, &Y);
          G[X].pb(Y);
          G[Y].pb(X);
    }
    for(i = 1; i <= N; i++)
          if(!niv[i])
          {
                     niv[i] = 1;
                     DFS(i);
          }
    printf("%i\n", C.size());
    for(i = 0; i < C.size(); i++)
    {
          for(j = 0; j < C[i].size(); j++) printf("%i ", C[i][j]);
          printf("\n");
    }
    return 0;
}