/*
* Author: Nonoze
* Created: Saturday 20/12/2025
*/
#include <bits/stdc++.h>
using namespace std;
#ifndef DEBUG
#define dbg(...)
#endif
// #define cout cerr << "OUT: "
#define endl '\n'
#define endlfl '\n' << flush
#define quit(x) return (void)(cout << x << endl)
template<typename T> void read(T& x) { cin >> x; }
template<typename T1, typename T2> void read(pair<T1, T2>& p) { read(p.first), read(p.second); }
template<typename T> void read(vector<T>& v) { for (auto& x : v) read(x); }
template<typename T1, typename T2> void read(T1& x, T2& y) { read(x), read(y); }
template<typename T1, typename T2, typename T3> void read(T1& x, T2& y, T3& z) { read(x), read(y), read(z); }
template<typename T1, typename T2, typename T3, typename T4> void read(T1& x, T2& y, T3& z, T4& zz) { read(x), read(y), read(z), read(zz); }
template<typename T> void print(vector<T>& v) { for (auto& x : v) cout << x << ' '; cout << endl; }
#define sz(x) (int)(x.size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define make_unique(v) sort(all(v)), v.erase(unique(all(v)), (v).end())
#define pb push_back
#define mp(a, b) make_pair(a, b)
#define fi first
#define se second
#define cmin(a, b) a = min(a, b)
#define cmax(a, b) a = max(a, b)
#define YES cout << "YES" << endl
#define NO cout << "NO" << endl
#define QYES quit("YES")
#define QNO quit("NO")
#define int long long
#define double long double
const int inf = numeric_limits<int>::max() / 4;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9+7, LOG=20;
void solve();
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);
int tt=1;
// cin >> tt;
while(tt--) solve();
return 0;
}
int n, k, m, q;
vector<int> cnt, nb, par;
vector<vector<pair<int, int>>> adj;
vector<vector<int>> empl;
map<int, int> dfs(int u, int p) {
vector<map<int, int>> children;
for (auto [v, id] : adj[u]) {
if (v == p) continue;
par[v]=u;
children.pb(dfs(v, u));
}
sort(rall(children), [](auto& a, auto& b) {
return sz(a) < sz(b);
});
map<int, int> curr;
if (sz(children)) curr = move(children[0]);
for (auto &x: empl[u]) {
curr[x]++;
if (curr[x] >= nb[x]) curr.erase(x);
}
for (int i=1; i<sz(children); i++) {
for (auto &[key, val] : children[i]) {
curr[key] += val;
if (curr[key] >= nb[key]) curr.erase(key);
}
}
cnt[u]=sz(curr);
return curr;
}
void solve() {
read(n, m, k);
adj.assign(n, {}), cnt.assign(n, 0), empl.assign(n, {}), par.assign(n, -1);
for (int i=0; i<n-1; i++) {
int u, v, w; read(u, v); u--, v--;
adj[u].pb({v, i});
adj[v].pb({u, i});
}
for (int i=0; i<m; i++) {
int sz; read(sz);
nb.pb(sz);
while (sz--) {
int x; read(x); x--;
empl[x].pb(i);
}
}
dfs(0, -1);
vector<int> ans;
for (int u=0; u<n; u++) {
for (auto &[v, id]: adj[u]) {
if (cnt[v]>=k && par[v]==u) {
ans.pb(id+1);
}
}
}
cout << sz(ans) << endl;
sort(all(ans));
print(ans);
}
