//Judges with GCC >= 12 only needs Ofast
//#pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
//MLE optimization
//#pragma GCC optimize("conserve-stack")
//Old judges
//#pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
//New judges. Test with assert(__builtin_cpu_supports("avx2"));
//#pragma GCC target("arch=skylake")
//Atcoder
//#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;
//template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//write variables and debug
#define bugf cout << "Here" << endl
#define bug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#define bugarr(arr,...) cout << #arr; _dbg_arr(arr, __VA_ARGS__)
template <class T>
ostream& operator<<(ostream& output, const vector<T> &arr){
int n = arr.size();
output << "[";
for(int i = 0; i < n; i++){
output << arr[i];
if(i != n - 1) output << ", ";
}
output << "]";
return output;
}
template<class T, class U>
ostream& operator<<(ostream& output, const pair<T, U> &A){
output << "(" << A.first << ", " << A.second << ")";
return output;
}
template<class T>
ostream& operator<<(ostream& output, const set<T> &s){
output << "{";
for(auto it = s.begin(); it != s.end(); it++){
if(it != s.begin()) output << ", ";
output << (*it);
}
output << "}";
return output;
}
template<class T, class U>
ostream& operator<<(ostream& output, const map<T, U> &m){
output << "{";
for(auto it = m.begin(); it != m.end(); it++){
if(it != m.begin()) output << ", ";
output << "(" << it->first << " : " << it->second << ")";
}
output << "}";
return output;
}
template<class TH>
void _dbg(const char *sdbg, TH h){
cout << sdbg << " = " << h << endl;
}
template<class TH, class... TA>
void _dbg(const char *sdbg, TH h, TA... a) {
while(*sdbg != ',')cout << *sdbg++;
cout << " = " << h << "\n";
_dbg(sdbg+1, a...);
}
template<class _Arr, class _Index>
void _dbg_arr(_Arr arr, _Index index){
cout << '[' << index << "] = " << arr[index] << endl;
}
template<class _Arr, class _Index, class... TA>
void _dbg_arr(_Arr &arr, _Index index, TA... args){
cout << '[' << index << ']';
_dbg_arr(arr[index], args...);
}
//open file
#define taskname "" //name input and output file
#ifdef SteGG
void open(){
if(fopen("input.inp", "r")){
freopen("input.inp", "r", stdin);
freopen("output.out", "w", stdout);
}
}
#else
void open(){
if(fopen(taskname".inp", "r")){
freopen(taskname".inp", "r", stdin);
freopen(taskname".out", "w", stdout);
}
}
#endif
//initialize
#define testcase \
long long test; \
cin >> test; \
for(int tst = 1; tst <= test; tst++)
#define int long long
#define MOD 1000000007
#define FFTMOD (119 << 23 | 1)
#define EPSILON 1e-9
#define setpre(x) fixed << setprecision(x)
#define cd complex<double>
#define all(x) x.begin(), x.end()
#define endl '\n'
const long long INF = 3e18L + 5;
const int inf = 1e9 + 7;
const double infd = 1e60;
const double PI = acos(-1);
const int maxn = 1e5 + 5;
//const int base = ;
int n, m, k;
vector<int> id_edges[maxn];
int sz_query[maxn];
vector<int> id_query[maxn];
unordered_map<int, int> *sus[maxn];
int finished[maxn];
vector<int> result;
//others struct or class
struct Edge{
int u, v;
Edge() : u(0), v(0) {}
Edge(int _u, int _v) : u(_u), v(_v) {}
int get(int _u){
if(_u == u) return v;
else return u;
}
};
//others function
//others init
Edge edges[maxn];
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
open();
cin >> n >> m >> k;
for(int i = 1; i < n; i++){
int u, v;
cin >> u >> v;
edges[i] = Edge(u, v);
id_edges[u].push_back(i);
id_edges[v].push_back(i);
}
for(int i = 1; i <= m; i++){
int sz;
cin >> sz;
sz_query[i] = sz;
for(int j = 1; j <= sz; j++){
int u;
cin >> u;
id_query[u].push_back(i);
}
}
function<int(int, int, int)> dfs = [&](int u, int p, int cur_id) -> int {
int sz_subtree = 1;
vector<int> children;
int largest = -1;
int max_sz = 0;
for(int id : id_edges[u]){
int v = edges[id].get(u);
if(v == p) continue;
children.push_back(v);
int temp = dfs(v, u, id);
if(largest == -1 || max_sz < temp){
max_sz = temp;
largest = v;
}
sz_subtree += temp;
}
if(largest == -1){
sus[u] = new unordered_map<int, int>();
finished[u] = 0;
}else{
sus[u] = sus[largest];
finished[u] = finished[largest];
}
for(int child : children){
if(child == largest) continue;
for(auto it = sus[child]->begin(); it != sus[child]->end(); it++){
int id_q = it->first;
int cnt = it->second;
(*sus[u])[id_q] += cnt;
if((*sus[u])[id_q] == sz_query[id_q]) finished[u]++;
}
}
for(int id_q : id_query[u]){
(*sus[u])[id_q]++;
if((*sus[u])[id_q] == sz_query[id_q]) finished[u]++;
}
if(sus[u]->size() - finished[u] >= k) result.push_back(cur_id);
return sz_subtree;
};
dfs(1, 0, -1);
sort(all(result));
cout << result.size() << endl;
for(int i = 0; i < result.size(); i++){
cout << result[i];
if(i != result.size() - 1) cout << " ";
else cout << endl;
}
return 0;
}
