#include <bits/stdc++.h>

#define pb push_back
#define ll long long
#define ld long double
#define sqr(a) (a) * (a)
#define F first
#define S second

using namespace std;

//mt19937 gen(time(0));

const int maxn = 1e4 + 10;

vector <int> g[maxn];
map <pair <int, int>, int> mp;
map <pair <int, int>, int> cnmp;
int tin[maxn];
int up[maxn];
int timer = 0;
bool dot[maxn];
bool bridge[maxn * 10];


void dfs(int v, int pr)
{
    timer++;
    tin[v] = timer;
    up[v] = timer;
    int cnt = 0;
    for(int to:g[v])
    {
        if (to == pr) continue;
        if (tin[to] == 0)
        {
            cnt++;
            dfs(to, v);
            up[v] = min(up[v], up[to]);
            if (up[to] >= tin[v] && pr != -1)
            {
                dot[v] = true;
            }
            int x = v;
            int y = to;
            if (y > x) swap(x, y);
            if (up[v] < up[to] && cnmp[make_pair(x, y)] == 1)
            {
                bridge[mp[make_pair(x, y)]] = true;
            }
        }
        else
        {
            up[v] = min(up[v], tin[to]);
        }
    }
    if (pr == -1 && cnt > 1)
    {
        dot[v] = true;
    }
    return;
}

int main()
{
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, m;
    cin >> n >> m;
    for(int i = 0; i < m; i++)
    {
        int x, y;
        cin >> x >> y;
        x--;
        y--;
        if (y > x) swap(x, y);
        g[x].pb(y);
        g[y].pb(x);
        mp[make_pair(x, y)] = i;
        cnmp[make_pair(x, y)]++;

    }
    for(int i = 0; i < n; i++)
        if (tin[i] == 0) dfs(i, -1);
    int cnt = 0;
    for(int i = 0; i < m; i++)
        if (bridge[i]) cnt++;
    cout << cnt << '\n';
    for(int i = 0; i < m; i++)
        if (bridge[i]) cout << i + 1 << '\n';

    cnt = 0;
    for(int i = 0; i < n; i++)
        if (dot[i]) cnt++;
    cout << cnt << '\n';
    for(int i = 0; i < n; i++)
        if (dot[i]) cout << i + 1 << '\n';
    return 0;
}