#include <cstdio>
#include <vector>
#include <bitset>
#include <stack>

#define Nmax 100005

using namespace std;

bitset<Nmax> used;
vector<int> G[Nmax];
vector<int> bix[Nmax];
stack<int> S;

int low[Nmax],niv[Nmax],nrb,N,M;



void Read()
{
    scanf("%d%d",&N,&M);
    int a,b;
    for(int i = 1; i <= M; ++i)
    {
        scanf("%d%d",&a,&b);
        G[a].push_back(b);
        G[b].push_back(a);
    }
}

void scoate(int k,int v)
{
    ++nrb;
    while(S.top() != v)
    {
        bix[nrb].push_back(S.top());
        S.pop();
    }
    bix[nrb].push_back(v);
    bix[nrb].push_back(k);
    S.pop();
}

void DFS(int k,int dad)
{
    used[k] = 1;
    niv[k] = niv[dad] + 1;
    low[k] = niv[k];
    for(vector<int>::iterator it = G[k].begin(); it != G[k].end(); ++it)
        if(!used[*it])
        {
            S.push(*it);
            DFS(*it,k);
            low[k] = min(low[k],low[*it]);

            if(low[*it] >= niv[k])
                scoate(k,*it);
        }
        else
            if(*it != dad && niv[*it] < low[k])
                low[k] = niv[*it];
}

void print()
{
    printf("%d\n",nrb);
    for(int i = 1; i <= nrb; ++i)
    {
        for(vector<int>::iterator it = bix[i].begin(); it != bix[i].end(); ++it)
            printf("%d ",*it);
        printf("\n");
    }
}

int main()
{
    freopen("biconex.in","r",stdin);
    freopen("biconex.out","w",stdout);

    Read();
    for(int i = 1; i <= N; ++i)
        if(!used[i])
        {
            S.push(i);
            DFS(1,0);
            S.pop();
        }
    print();

    return 0;
}