#include "bits/extc++.h"
using namespace std;
template <typename T>
void dbgh(const T& t) {
cerr << t << endl;
}
template <typename T, typename... U>
void dbgh(const T& t, const U&... u) {
cerr << t << " | ";
dbgh(u...);
}
#ifdef DEBUG
#define dbg(...) \
cerr << "L" << __LINE__ << " [" << #__VA_ARGS__ << "]" \
<< ": "; \
dbgh(__VA_ARGS__)
#else
#define cerr \
if (false) \
cerr
#define dbg(...)
#endif
#define endl "\n"
#define long int64_t
#define sz(x) int((x).size())
const int maxn = 1e5 + 5, logn = 20;
int t, tin[maxn], tout[maxn], lift[logn][maxn];
vector<int> graph[maxn];
void dfs(int u, int p = -1) {
tin[u] = t++;
lift[0][u] = p;
for (auto& v : graph[u]) {
if (v != p) {
dfs(v, u);
}
}
tout[u] = t++;
}
bool anc(int u, int v) {
return tin[u] <= tin[v] && tout[v] <= tout[u];
}
int lca(int u, int v) {
if (anc(u, v)) {
return u;
}
for (int i = logn - 1; i >= 0; i--) {
int nu = lift[i][u];
if (nu != -1 && !anc(nu, v)) {
u = nu;
}
}
return lift[0][u];
}
void solve() {
int n, q, k;
cin >> n >> q >> k;
int edges[n - 1][2];
for (auto& [u, v] : edges) {
cin >> u >> v;
u--;
v--;
graph[u].push_back(v);
graph[v].push_back(u);
}
dfs(0);
for (int i = 1; i < logn; i++) {
for (int j = 0; j < n; j++) {
if (lift[i - 1][j] == -1) {
lift[i][j] = -1;
} else {
lift[i][j] = lift[i - 1][lift[i - 1][j]];
}
}
}
int psum[n * 2 + 1] {};
auto add = [&](int l, int r) -> void {
psum[l]++;
psum[r + 1]--;
};
while (q--) {
dbg("Q");
int m;
cin >> m;
int arr[m];
for (auto& a : arr) {
cin >> a;
a--;
}
sort(arr, arr + m, [&](int a, int b) -> bool {
return tin[a] < tin[b];
});
vector<int> vtree(arr, arr + m);
for (int i = 0; i < m - 1; i++) {
vtree.push_back(lca(arr[i], arr[i + 1]));
}
sort(begin(vtree), end(vtree), [&](int a, int b) -> bool {
return tin[a] < tin[b];
});
vtree.erase(unique(begin(vtree), end(vtree)), vtree.end());
vector<int> stk;
for (auto& a : vtree) {
dbg(a);
}
for (auto& a : vtree) {
while (sz(stk) && !anc(stk.back(), a)) {
stk.pop_back();
}
if (sz(stk)) {
dbg(stk.back(), a);
add(tin[stk.back()] + 1, tin[a]);
}
stk.push_back(a);
}
}
for (int i = 0; i < 2 * n; i++) {
psum[i + 1] += psum[i];
}
for (int i = 0; i < n; i++) {
dbg(i, psum[tin[i]] - psum[tout[i]]);
}
vector<int> ans;
for (int i = 0; i < n - 1; i++) {
auto [u, v] = edges[i];
if (lift[0][u] == v) {
swap(u, v);
}
if (psum[tin[v]] - psum[tout[v]] >= k) {
ans.push_back(i);
}
}
cout << sz(ans) << endl;
for (int i = 0; i < sz(ans); i++) {
cout << ans[i] + 1 << " \n"[i == sz(ans) - 1];
}
}
int main() {
cin.tie(nullptr);
ios_base::sync_with_stdio(false);
cin.exceptions(ios::failbit);
solve();
}
