#include<bits/stdc++.h>
using namespace std ;
const int N = (1 << 15) ;
int n , m , k ;
int st[N] , en[N] ;
vector<int> deps[N ] , ans ;
int t = 3;
int L[N] , R[N] ;
vector<pair<int , int > > adj[N] ;
//////
long long f(long long x, long long y)
{
return x + y ;
}
struct node
{
long long sum = 0;
node *l, *r;
node(long long _sum) : sum(_sum), l(nullptr), r(nullptr)
{
}
node(node *_l, node *_r) : l(_l), r(_r), sum(0)
{
if (l)
sum = f(sum, l->sum);
if (r)
sum = f(sum, r->sum);
}
};
node *update(node *nod, int L, int R, int idx, long long val)
{
if (L == R)
{
nod->sum = f(val , nod -> sum ) ;
return nod;
}
int mid = (L + R) >> 1;
if (idx <= mid)
{
if (nod->l == NULL)
{
nod->l = new node(0);
}
return new node(update(nod->l, L, mid, idx, val), nod->r);
}
else
{
if (nod->r == NULL)
{
nod->r = new node(0);
}
return new node(nod->l, update(nod->r, mid + 1, R, idx, val));
}
}
long long query(node *nod, int L, int R, int l, int r)
{
if (l > r || l > R || r < L || nod == NULL)
return 0;
if (L >= l && R <= r)
{
return nod->sum;
}
int mid = (L + R) >> 1;
long long s1 = query(nod->l, L, mid, l, r);
long long s2 = query(nod->r, mid + 1, R, l, r);
return f(s1, s2);
}
struct node2
{
node *sum = new node(0);
node2 *l, *r;
node2() : l(nullptr), r(nullptr)
{
}
node2(node2 *_l, node2 *_r) : l(_l), r(_r)
{
}
};
long long query2(node2 *nod, int L, int R, int l, int r, int x, int y)
{
if (l > R || r < L || l > r || nod == NULL)
return 0;
if (L >= l && R <= r)
{
return query(nod->sum, 1, N, x, y);
}
int mid = (L + R) >> 1;
long long s1 = query2(nod->l, L, mid, l, r, x, y);
long long s2 = query2(nod->r, mid + 1, R, l, r, x, y);
return f(s1, s2);
}
void upd(node2 *nod, int L, int R, int x, int y, long long z)
{
if (L == R)
{
nod->sum = update(nod->sum, 1, N, y, z);
return;
}
int mid = (L + R) >> 1;
long long add = 0;
if (x <= mid)
{
if (nod->l == NULL)
{
nod->l = new node2();
}
upd(nod->l, L, mid, x, y, z);
}
else
{
if (nod->r == NULL)
{
nod->r = new node2();
}
upd(nod->r, mid + 1, R, x, y, z);
}
nod->sum = update(nod->sum, 1, N, y, z );
return;
}
node2 *root = new node2() ;
node2 *root2 = new node2() ;
/////
void dfz(int x , int p){
st[x] = ++ t;
for(auto u : adj[x]){
if( u.first == p)
continue ;
dfz(u.first ,x ) ;
}
en[x] = ++t ;
return ;
}
vector<pair<int , int > > vs ;
void dfs(int x , int p){
for(auto u: adj[x]){
if(u.first == p)
continue ;
int cnt = m ;
cnt -= query2(root , 1 , N , 1 , st[u.first] , en[u.first] , N ) ;
cnt -= query2(root2 , 1 , N , st[u.first] , N , 1 , en[u.first] ) ;
if(cnt>= k){
ans.push_back(u.second + 1) ;
}
dfs(u .first, x) ;
}
return ;
}
int main(){
ios_base::sync_with_stdio(0) ;
cin.tie(0) ;
//freopen("in.in" , "r" , stdin) ;
cin >> n >> m >> k ;
for(int i = 0 ; i < n-1 ;i ++){
int u , v;
cin >> u >> v;
adj[u].push_back({v , i }) ;
adj[v].push_back({u , i}) ;
}
dfz(1 , 1) ;
for(int i = 0 ;i < m ;i++){
int x ; cin >> x ;
vector<int> vec ;
for(int j = 0 ;j < x ;j++){
int t ; cin >> t ;
deps[i].push_back(t) ;
vec.push_back(st[t]) ;
}
sort(vec.begin() , vec.end()) ;
int l = 1 ;
for(auto u: vec){
if(u > l && l+1 <= u-1 ){
vs.push_back({l +1 , u -1 }) ;
upd(root ,1 , N , l+1 , u - 1 , 1) ;
}
l = u ;
}
L[i] = vec[0] ;
R[i] = vec.back() ;
upd(root2 ,1 , N , L[i] , R[i] , 1) ;
vs.push_back({l+1 , N -1}) ;
upd(root , 1 , N , l+1 , N-1 , 1) ;
}
dfs( 1, 1) ;
cout<< (int) ans.size() <<"\n" ;
sort(ans.begin() , ans.end()) ;
for(auto u : ans){
cout<< u <<" " ;
}
return 0 ;
}
