#include <bits/stdc++.h>
#define int long long
std::vector<std::pair<int,int>> adj[100010];
std::vector<int> ans;
int n,m,k;
int diff[100010];
int depth[100010];
int cid=0;
int id[100010];
int mxid[100010];
int arr[100010];
int bilift[100010][23];
void construct(int curr,int par){
mxid[curr]=id[curr]=cid++;
depth[curr]=depth[par]+1;
if(curr==1){
for(int i=1;i<=20;i++){
bilift[curr][i]=1;
}
}
else{
bilift[curr][0]=par;
for(int i=1;i<=20;i++){
bilift[curr][i]=bilift[bilift[curr][i-1]][i-1];
}
}
for(auto [to,idx]:adj[curr]){
if(to==par)continue;
mxid[curr]=std::max(mxid[curr],mxid[curr]);
construct(to,curr);
}
}
void dfs(int curr,int par,int req){
req+=diff[curr];
for(auto [to,idx]:adj[curr]){
if(to==par)continue;
if(req>=k)ans.push_back(idx);
dfs(to,curr,req);
}
}
int lca(int n1,int n2){
if(depth[n2]>depth[n1])std::swap(n1,n2);
for(int i=20;i>=0;i--){
if(depth[bilift[n1][i]]>=depth[n2])n1=bilift[n1][i];
}
if(n1==n2)return n1;
for(int i=20;i>=0;i--){
if(bilift[n1][i]!=bilift[n2][i])n1=bilift[n1][i],n2=bilift[n2][i];
}
return bilift[n1][0];
}
signed main() {
std::cin >> n >> m >> k;
for(int i=0;i<n-1;i++){
int in1,in2;
std::cin >> in1 >> in2;
adj[in1].push_back({in2,i});
adj[in2].push_back({in1,i});
}
construct(1,1);
for(int i=0;i<m;i++){
std::set<std::pair<std::pair<int,int>,int>> st;
int amt;
std::cin >> amt;
int aLca;
std::cin >> aLca;
st.insert({{id[aLca],mxid[aLca]},aLca});
for(int i=1;i<amt;i++){
int in;
std::cin >> in;
aLca=lca(aLca,in);
auto itr=st.upper_bound({{id[in],(int)-1e18},(int)-1e18});
auto itr2=itr;
if(itr2!=st.begin()){
itr2--;
if(itr2->first.second>=mxid[in]){
st.erase(itr2);
}
}
if(itr!=st.end()&&itr->first.second<=mxid[in]){
st.insert({{id[in],mxid[in]},in});
}
}
diff[aLca]+=1;
for(auto [p,idx]:st){
diff[idx]-=1;
}
}
dfs(0,0,0);
std::sort(ans.begin(),ans.end());
std::cout << ans.size() << '\n';
for(auto edge:ans)std::cout << edge << ' ';
}
