#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define pll pair<ll, ll>
#define sz(x) int(x.size())
using namespace std;
const int maxn = 100100;
const int maxlog = 20;
vector<int>g[maxn];
vector<int>gt[maxn];
ll n, q, k;
int opent[maxn], euler[maxn];
int sbtsize[maxn], br;
int depth[maxn];
int parent[maxn][maxlog];
void dfs_preprocess(int node, int p, int d) {
opent[node] = br;
euler[br] = node;
sbtsize[node] = 1;
depth[node] = d;
br++;
parent[node][0] = p;
for(int i:g[node]) {
if(i == p) continue;
dfs_preprocess(i, node, d + 1);
sbtsize[node] += sbtsize[i];
}
}
void lca_preprocess() {
for(int level=1;level<maxlog;level++) {
for(int i=1;i<=n;i++) {
if(parent[i][level-1] == -1) continue;
parent[i][level] = parent[parent[i][level-1]][level-1];
}
}
}
int lca(int a, int b) {
if(depth[a] > depth[b]) swap(a, b);
if(opent[b] >= opent[a] && opent[b] < opent[a] + sbtsize[a]) return a;
for(int i=maxlog-1;i>=0;i--) {
if(parent[a][i] == -1) continue;
int nextnode = parent[a][i];
if(opent[b] < opent[nextnode] || opent[b] >= opent[nextnode] + sbtsize[nextnode]) a = nextnode;
}
return parent[a][0];
}
int start_here[maxn], end_here[maxn];
map<pii, int> ind;
vector<int>result;
int dfs_count(int node, int p) {
int sum = 0;
for(int i:g[node]) {
if(i == p) continue;
int tmp = dfs_count(i, node);
if(tmp >= k) {
result.pb(ind[mp(i, node)]);
}
sum += tmp;
}
return sum + start_here[node] - end_here[node];
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin>>n>>q>>k;
ll u, v;
for(int i=0;i<n-1;i++) {
cin>>u>>v;
g[u].pb(v);
g[v].pb(u);
ind[mp(u, v)] = ind[mp(v, u)] = i + 1;
}
memset(parent, -1, sizeof(parent));
dfs_preprocess(1, -1,0);
lca_preprocess();
int s;
bool root;
while(q--) {
cin>>s;
vector<pii> v;
set<int>st;
for(int i=0;i<s;i++) {
cin>>u;
v.pb(mp(opent[u], u));
st.insert(u);
}
sort(v.begin(), v.end());
for(int i=1;i<sz(v);i++) {
st.insert(lca(v[i].second, v[i-1].second));
}
v.clear();
for(int i:st) {
v.pb(mp(opent[i], i));
} sort(v.begin(), v.end());
stack<int>node_stack;
node_stack.push(v[0].second);
for(int i=1;i<sz(v);i++) {
while(!node_stack.empty()) {
int curr = node_stack.top();
int nextnode = v[i].second;
if(opent[nextnode] >= opent[curr] && opent[nextnode] < opent[curr] + sbtsize[curr]) {
start_here[nextnode]++;
end_here[curr]++;
node_stack.push(nextnode);
break;
}
else {
node_stack.pop();
}
}
}
}
dfs_count(1, -1);
sort(result.begin(), result.end());
cout<<sz(result)<<"\n";
for(int i:result) {
cout<<i<<" ";
} cout<<"\n";
}
