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

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

vector<int> G[nmax], c;
stack<pair<int, int> > S;
vector<vector<int> > C;
int N, M, x, y, niv[nmax], low[nmax];


void Comp(int x, int y)
{
     c.clear();
     pair<int, int> p;
     do
     {
               p = S.top();
               S.pop();
               c.pb(p.to);
     }while(p.from != x && p.to != y);
     c.pb(p.from);
     C.pb(c);
}


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


int main()
{
    freopen("biconex.in", "r", stdin);
    freopen("biconex.out", "w", stdout);
    int i, j;
    scanf("%i %i", &N, &M);
    for(i = 0; 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");
    }
    scanf("%i", &i);
    return 0;
}