#include <iostream>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <string>

#include <algorithm>

#include <cmath>

#include <ctime>

#include <vector>

#include <queue>

#include <map>

#include <stack>

#include <set>

#include <bitset>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

#define ms(a, b) memset(a, b, sizeof(a))

#define pb push_back

#define mp make_pair

#define pii pair<int, int>

#define eps 0.0000000001

#define IOS ios::sync_with_stdio(0);cin.tie(0);

#define random(a, b) rand()*rand()%(b-a+1)+a

#define pi acos(-1)

const ll INF = 0x3f3f3f3f3f3f3f3fll;

const int inf = 0x3f3f3f3f;

const int maxn =  + ;

const int maxm =  + ;

const int mod = 1e9+;

struct ND{

    int v,nxt;

    ND(){}

    ND(int _v,int _nxt):v(_v),nxt(_nxt){}

}e[maxn*];

bool pvis[maxn],evis[maxn*];

int head[maxn],du[maxn],tot;

int n,m,cnt;

vector<int> ans[maxn],odd;

void init(){

    cnt=tot=;

    memset(head,-,sizeof(head));

    memset(du,,sizeof(du));

    memset(pvis,false,sizeof(pvis));

    memset(evis,false,sizeof(evis));

    for(int i=;i<=n;i++) ans[i].clear();

}

void addedge(int u,int v){

    e[tot]=ND(v,head[u]);head[u]=tot++;

    e[tot]=ND(u,head[v]);head[v]=tot++;

}

void dfs1(int u){

    pvis[u]=true;

    if(du[u]%) odd.push_back(u);//同一联通块里奇数度的点

    for(int i=head[u];~i;i=e[i].nxt){

        int v = e[i].v;

        if(!pvis[v]){

            dfs1(v);

        }

    }

}

void dfs2(int u){

    for(int i=head[u];~i;i=e[i].nxt){

        int v=e[i].v;

        if(!evis[i]){

            evis[i]=evis[i^]=true;//判断边有没有走过

            dfs2(v);

            int tmp=i%?-(i+)/:i/+; //对应边的编号

            if(i<*m) ans[cnt].push_back(tmp); //为原先存在的边

            else cnt++; //新连的虚边

        }

    }

}

int main(){

#ifdef LOCAL

    freopen("in.txt", "r", stdin);

//    freopen("output.txt", "w", stdout);

#endif

    while(~scanf("%d%d",&n,&m)){

        init();

        int u,v;

        for(int i=;i<m;i++){

            scanf("%d%d",&u,&v);

            addedge(u,v);

            du[u]++,du[v]++;

        }

        for(int i=;i<=n;i++){

            if(!pvis[i]&&du[i]){

                odd.clear();

                dfs1(i);

                for(int i=;i<odd.size();i+=){//保留两个奇度点，其余两两连边

                    addedge(odd[i],odd[i+]);

                }

                int rt = odd.size()?odd[]:i;

                dfs2(rt);

                cnt++;

            }

        }

        printf("%d\n",cnt);

        for(int i=;i<cnt;i++){

            printf("%d",ans[i].size());

            for(int j=ans[i].size()-;j>=;j--){

                printf(" %d",ans[i][j]);

            }puts("");

        }

    }

    return ;

}