#include<stdio.h>
#define Nmx 200001
#include<vector>

using namespace std;

int n,m;
struct dat
{
    int x,y;
}s[Nmx];
vector<int> G[Nmx];
vector<int> sol[Nmx];
int lvl[Nmx],nr,c[Nmx],nrsol,viz[Nmx];

void citire()
{
    scanf("%d%d",&n,&m);
    int x,y;
    for(int i=1;i<=m;++i)
    {
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void add(int x,int y)
{
    nrsol++;
    do{
        sol[nrsol].push_back(s[nr].y);
        nr--;
    }while(s[nr+1].x!=x||s[nr+1].y!=y);
    sol[nrsol].push_back(s[nr+1].x);
}

void dfs(int nod,int tata)
{
    lvl[nod]=lvl[tata]+1;
    c[nod]=lvl[nod];
    viz[nod]=1;
    for(int i=0;i<G[nod].size();++i)
    {
        int x=G[nod][i];
        if(!viz[x])
        {
            s[++nr].x=nod;
            s[nr].y=x;
            dfs(x,nod);
            if(c[x]<c[nod])
                c[nod]=c[x];
            if(c[x]>=lvl[nod])
                add(nod,x);
        }
        else if(tata!=x&&c[x]<c[nod])
            c[nod]=c[x];
    }
}

void afisare()
{
    printf("%d\n",nrsol);
    for(int i=1;i<=nrsol;++i)
    {
        for(int j=0;j<sol[i].size();++j)
            printf("%d ",sol[i][j]);
        printf("\n");
    }
}

int main()
{
    freopen("biconex.in","r",stdin);
    freopen("biconex.out","w",stdout);
    citire();
    dfs(1,0);
    afisare();
    return 0;
}