/*Huyyt*/

#include<bits/stdc++.h>

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

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const double eps = 1e-;

const int dir[][] = {{, }, {, }, {, -}, { -, }, {, }, {, -}, { -, -}, { -, }};

const int mod = 1e9 + , gakki =  +  +  +  + 1e9;

const int MAXN = 1e5 + , MAXM = 2e5 + , MAXQ = , INF = 1e9;

const ll LLINF = (1LL << );

int to[MAXM << ], nxt[MAXM << ], Head[MAXN], tot = ;

int index[MAXM << ];

bool used[MAXM << ];

inline void addedge(int u, int v, int x)

{

        if (u == v)

        {

                return ;

        }

        to[++tot] = v;

        nxt[tot] = Head[u];

        index[tot] = x;

        used[tot] = false;

        Head[u] = tot;

}

inline void read(int &v)

{

        v = ;

        char c = ;

        int p = ;

        while (c < '' || c > '')

        {

                if (c == '-')

                {

                        p = -;

                }

                c = getchar();

        }

        while (c >= '' && c <= '')

        {

                v = (v << ) + (v << ) + c - '';

                c = getchar();

        }

        v *= p;

}

int n, m;

int du[];

bool visit[];

int ans = ;

vector<int> anser[];

int cnt = ;

void dfs(int x)

{

        int nowindex;

        visit[x] = true;

        for (int v, i = Head[x]; i; i = nxt[i])

        {

                v = to[i];

                if (used[i])

                {

                        continue;

                }

                used[i] = used[i ^ ] = true;

                nowindex = index[i];

                //cout << x << " to " << v << " index " << nowindex << " i " << i << endl;

                dfs(v);

                if (nowindex == )

                {

                        anser[++cnt].clear();

                }

                else

                {

                        anser[cnt].push_back(-nowindex);

                }

        }

}

int main()

{

        ios_base::sync_with_stdio();

        cin.tie();

        int u, v;

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

        {

                cnt = ;

                tot = ;

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

                {

                        du[i] = ;

                        visit[i] = false;

                        Head[i] = ;

                }

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

                {

                        read(u), read(v);

                        addedge(u, v, i);

                        addedge(v, u, -i);

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

                }

                int aim = ;

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

                {

                        if (du[i] & )

                        {

                                if (aim)

                                {

                                        addedge(aim, i, );

                                        addedge(i, aim, );

                                        aim = ;

                                }

                                else

                                {

                                        aim = i;

                                }

                        }

                }

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

                {

                        if (!visit[i] && (du[i] & ))

                        {

                                anser[++cnt].clear();

                                dfs(i);

                                cnt--;

                        }

                }

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

                {

                        if (!visit[i] && du[i])

                        {

                                anser[++cnt].clear();

                                dfs(i);

                        }

                }

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

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

                {

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

                        for (int j = ; j < anser[i].size(); j++)

                        {

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

                                if (j == anser[i].size() - )

                                {

                                        putchar('\n');

                                }

                                else

                                {

                                        putchar(' ');

                                }

                        }

                }

        }

        return ;

}