#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 10;
int pre[MAXN], s[MAXN];
vector<int> adj[MAXN];
int t = 0;
void dfs(int v, int p){
pre[v] = ++t;
for(auto u : adj[v]){
if(u != p){
dfs(u, v);
}
}
}
int main(){
cin.tie(0)->sync_with_stdio(0);
int n, m, k; cin >> n >> m >> k;
vector<pair<int, int>> edges;
for(int i=1; i<n; i++){
int a, b; cin >> a >> b;
edges.push_back({a, b});
adj[a].push_back(b);
adj[b].push_back(a);
}
dfs(1, 1);
while(m--){
int k; cin >> k;
int l = n + 1, r = 0;
for(int i=0; i<k; i++){
int v; cin >> v;
l = min(l, pre[v]);
r = max(r, pre[v]);
}
s[l] ++;
s[r + 1] --;
}
for(int i=1; i<=n; i++) s[i] += s[i - 1];
vector<int> ans;
for(int i=0; i<(int) edges.size(); i++){
if(s[max(pre[edges[i].first], pre[edges[i].second])] > k){
ans.push_back(i + 1);
}
}
cout << (int) ans.size() << "\n";
for(auto x : ans) cout << x << " ";
cout << "\n";
return 0;
}
