#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define F first
#define S second
const int N = 1e5+3;
vector<int> adj[N];
int p[N][17];
int tin[N], tout[N];
int timer=-1;
void dfs(int v, int par){
p[v][0]=par;
for(int i=1; i<17; i++){
p[v][i]=p[p[v][i-1]][i-1];
}
timer++;
tin[v]=timer;
for(int to : adj[v]){
if(to!=par)dfs(to, v);
}
tout[v]=timer;
}
bool anc(int a, int b){
return (tin[a]<=tin[b] && tout[a]>=tout[b]);
}
int lca(int a, int b){
if(anc(a, b))return a;
if(anc(b, a))return b;
int ret=a;
for(int i=16; i>=0; i--){
if(!anc(p[ret][i], b)){
ret=p[ret][i];
}
}
return p[ret][0];
}
struct minister{
int n;
vector<pair<int, int>> nodes;
};
minister a[N/2];
int val[N];
int bring=0;
void dfs2(int v, int par){
for(int to : adj[v]){
if(to!=par){
dfs2(to, v);
val[v]+=bring;
bring=0;
}
}
bring+=val[v];
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, m, k;
cin >> n >> m >> k;
vector<pair<int, int>> edges(n-1);
for(int i=0; i< n-1; i++){
cin >> edges[i].F >> edges[i].S;
adj[edges[i].F].pb(edges[i].S);
adj[edges[i].S].pb(edges[i].F);
}
dfs(1, 0);
tin[0]=-1;
tout[0]=1e9;
for(int i=0; i< n-1; i++){
if(anc(edges[i].S, edges[i].F))swap(edges[i].F, edges[i].S);
}
for(int i = 0; i< m; i++){
cin >> a[i].n;
for(int j=0; j< a[i].n; j++){
int x;
cin >> x;
a[i].nodes.pb({tin[x], x});
}
sort(a[i].nodes.begin(), a[i].nodes.end());
int lc=a[i].nodes[0].S;
for(int j=0; j< a[i].n-1; j++)val[lca(a[i].nodes[j].S, a[i].nodes[j+1].S)]--;
for(int j=0; j<a[i].n; j++)val[a[i].nodes[j].S]++;
for(int j=1; j<a[i].n; j++)lc=lca(lc, a[i].nodes[j].S);
val[lc]--;
}
dfs2(1, 0);
vector<int> ans;
for(int i=0; i< n-1; i++){
if(val[edges[i].S]>=k)ans.pb(i+1);
}
sort(ans.begin(), ans.end());
cout << ans.size() << '\n';
for(int e : ans)cout << e << ' ';
}
