//#pragma GCC optomize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
//#pragma GCC target("sse,sse2,sse4.1,sse4.2")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define max_heap priority_queue<pair <ll, pair <ll, ll>>>
#define min_heap priority_queue<pair <ll, ll>, vector<pair <ll, ll>>, greater<pair <ll, ll>>>
//#define min_heap priority_queue<ll, vector<ll>, greater<ll>>
#define sariE cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define filE freopen("in.txt", "r", stdin); freopen("out1.txt", "w", stdout);
#define endl '\n'
#define md(a) (a % mod + mod) % mod
#define pb push_back
//cout << vectorprecision(5) << fixed << f;
//hash prime = 769
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll const maxn = 2e5 + 123;
ll const inf = 2e18;
ll const loG = 23;
ll const mod = 1e9 + 7;
//ll const mod = 998244353;
ll const sq = 400;
ll power(ll a, ll b, ll mod){if(b==0)return 1;if(b==1)return a;ll x = power(a, b / 2, mod);return (((x * x) % mod) * (b % 2 ? a : 1)) % mod;}
ll n, q, k, st[maxn], stt[maxn], fn[maxn], h[maxn], par[loG][maxn], sz[maxn], big[maxn], head[maxn], op[maxn * 2], tim, tim2, segsz = 2;
vector <ll> g[maxn], seg;
vector <pair <pair <ll, ll>, ll>> yal;
void dfs(ll v, ll p){
sz[v] = 1;
par[0][v] = p;
h[v] = h[p] + 1;
big[v] = 0;
stt[v] = ++tim2;
for (ll u : g[v]){
if (u != p){
dfs(u, v);
if (sz[u] > sz[big[v]]){
big[v] = u;
}
sz[v] += sz[u];
}
}
fn[v] = ++tim2;
}
void dfs_hld(ll v, ll p, ll baba){
st[v] = ++tim;
head[v] = baba;
if (big[v]){
dfs_hld(big[v], v, baba);
}
for (ll u : g[v]){
if ((u == p) || (u == big[v]))
continue;
dfs_hld(u, v, u);
}
}
void propogate(ll x, ll lx, ll rx){
if (rx - lx == 1)
return;
if (op[x] == 0)
return;
ll mid = (lx + rx) / 2, a = 2 * x + 1, b = a + 1;
op[a] += op[x];
op[b] += op[x];
seg[a] += (mid - lx) * op[x];
seg[b] += (rx - mid) * op[x];
op[x] = 0;
}
ll getter(ll i, ll x, ll lx, ll rx){
propogate(x, lx, rx);
if (rx - lx == 1)
return seg[x];
ll mid = (lx + rx) / 2, a = 2 * x + 1, b = a + 1;
ll val = 0;
if (i < mid)
val = getter(i, a, lx, mid);
else
val = getter(i, b, mid, rx);
seg[x] = seg[a] + seg[b];
return val;
}
void adder(ll l, ll r, ll x, ll lx, ll rx){
//cout << l << ' ' << r << ' ' << x << ' ' << lx << " " << rx << ' ' << getter(l, 0, 0, segsz) << ' ' << getter(r - 1, 0, 0, segsz) << endl;
propogate(x, lx, rx);
if (l >= rx || lx >= r)
return;
if (l <= lx && rx <= r){
seg[x] += (rx - lx);
op[x] += 1;
return;
}
ll mid = (lx + rx) / 2, a = 2 * x + 1, b = a + 1;
adder(l, r, a, lx, mid);
adder(l, r, b, mid, rx);
seg[x] = seg[a] + seg[b];
}
ll jump(ll v, ll d){
for (int i = 0; i < loG; i++)
if (d & (1 << i))
v = par[i][v];
return v;
}
ll lca(ll u, ll v){
if (h[u] < h[v])
swap(u, v);
u = jump(u, h[u] - h[v]);
if (u == v) return u;
for (int i = loG - 1; i >= 0; i--)
if (par[i][u] != par[i][v])
u = par[i][u],
v = par[i][v];
return par[0][u];
}
bool cmp(ll v, ll u){
return stt[v] < stt[u];
}
bool ispar(ll v, ll u){
return (stt[v] <= stt[u]) && (fn[v] >= fn[u]);
}
void add(ll v, ll u){
while (head[v] != head[u]){
if (h[head[v]] < h[head[u]]){
swap(u, v);
}
adder(st[head[v]], st[v] + 1, 0, 0, segsz);
//cout << "adding " << head[v] << ' ' << v << endl;
v = par[0][head[v]];
}
if (h[v] > h[u])
swap(v, u);
//cout << "adding " << v << ' ' << u << endl;
adder(st[v], st[u] + 1, 0, 0, segsz);
}
void Solve(){
cin >> n >> q >> k;
while (segsz <= n * 2)
segsz = segsz * 2;
seg.resize(2 * segsz);
for (int i = 1; i < n; i++){
ll a, b; cin >> a >> b;
yal.pb({{a, b}, i});
g[a].pb(b);
g[b].pb(a);
}
dfs(1, 1);
dfs_hld(1, 1, 1);
for (int i = 1; i < loG; i++)
for (int j = 1; j < n + 1; j++)
par[i][j] = par[i - 1][par[i - 1][j]];
while (q--){
ll m; cin >> m;
vector <ll> tmp, stk; tmp.clear(); stk.clear();
for (int i = 1; i < m + 1; i++){
ll x; cin >> x;
tmp.pb(x);
}
sort(tmp.begin(), tmp.end(), cmp);
for (int i = 0; i < tmp.size() - 1; i++){
ll a = tmp[i], b = tmp[i + 1], c = lca(a, b);
stk.pb(c);
}
for (ll x : stk)
tmp.pb(x);
sort(tmp.begin(), tmp.end(), cmp); tmp.resize(unique(tmp.begin(), tmp.end()) - tmp.begin());
stk.clear();
for (ll v : tmp){
while (stk.size() && !ispar(stk.back(), v))
stk.pop_back();
if (stk.size()){
// kar
ll x = stk.back();
ll e = h[v] - h[x];
ll xx = jump(v, e - 1);
add(v, xx);
//cout << "yal " << v << ' ' << x << ' ' << xx << endl;
}
stk.pb(v);
}
//cout << "new qu" << endl;
}
// for (int i = 1; i < n + 1; i++){
// cout << i << ' ' << st[i] << ' ' << getter(st[i], 0, 0, segsz) << endl;
// }
vector <ll> ans; ans.clear();
for (auto p : yal){
ll a = p.first.first, b = p.first.second;
ll x = getter(max(st[a], st[b]), 0, 0, segsz);
//cout << a << ' ' << b << ' ' << st[a] << ' ' << st[b] << ' ' << x << endl;
if (x >= k)
ans.pb(p.second);
}
cout << ans.size() << endl;
for (ll x : ans)
cout << x << ' ';
cout << endl;
}
int main(){
sariE;// filE;
int test = 1;
//cin >> test;
while (test--) Solve();
return 0;
}
