#include<bits/stdc++.h>
using namespace std;
struct LCA{
int n;
vector<vector<int>> jump;
vector<int> dep;
void dfs(int u, int p, int d, vector<vector<int>>& G, vector<int>& used){
if(used[u]) return;
dep[u] = d;
used[u] = 1;
jump[u][0] = p;
for(int v : G[u]) dfs(v,u,d+1,G,used);
}
void init(int n1, vector<vector<int>>& G){
n = n1;
jump.assign(n+1,vector<int>(25,1));
dep.assign(n+1,0);
vector<int> used(n+1,0);
dfs(1,1,0,G,used);
for(int k = 1; k<25; k++){
for(int u = 1; u<=n; u++){
jump[u][k] = jump[jump[u][k-1]][k-1];
}
}
}
int LCAA(int a, int b){
if(dep[a] > dep[b]) swap(a,b);
int x = dep[b]-dep[a];
for(int i = 0; i<25; i++){
if(x & (1<<i)){
b = jump[b][i];
}
}
if(a == b) return a;
for(int i = 24; i>=0; i--){
if(jump[a][i] != jump[b][i]){
a = jump[a][i];
b = jump[b][i];
}
}
return jump[a][0];
}
};
int n,m,k;
vector<vector<int>> G;
vector<vector<int>> isLCA, FromU;
vector<set<int>> SmtoLG;
vector<int> used, fromk;
void dfs(int u){
if(used[u]) return;
used[u] = 1;
for(int v : G[u]){
if(used[v]) continue;
dfs(v);
if(SmtoLG[v].size() > SmtoLG[u].size()) swap(SmtoLG[u], SmtoLG[v]);
for(auto x : SmtoLG[v]) SmtoLG[u].insert(x);
}
for(auto x : FromU[u]) SmtoLG[u].insert(x);
if(u != 1) for(auto x : isLCA[u]) SmtoLG[u].erase(x);
fromk[u] = SmtoLG[u].size();
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin>>n>>m>>k;
G.assign(n+1,vector<int>()); isLCA = G; FromU = isLCA;
map<pair<int,int>,int> edge;
for(int i = 1; i<n; i++){
int u,v; cin>>u>>v;
G[u].push_back(v);
G[v].push_back(u);
pair<int,int> p = {u,v};
edge[p] = i;
swap(p.first,p.second);
edge[p] = i;
}
LCA LC; LC.init(n,G);
for(int i = 0; i<m; i++){
int x; cin>>x;
int a,b; cin>>a>>b;
FromU[a].push_back(i); FromU[b].push_back(i);
int lc = LC.LCAA(a,b);
for(int j = 0; j<x-2; j++){
int c; cin>>c;
FromU[c].push_back(i);
lc = LC.LCAA(lc,c);
}
isLCA[lc].push_back(i);
}
SmtoLG.resize(n+1);
used.assign(n+1,0); fromk = used;
dfs(1);
vector<int> ans;
for(int i = 2; i<=n; i++){
//cout<<fromk[i]<<" ";
if(fromk[i] >= k){
// cerr<<i<<" "<<LC.jump[i][0]<<endl;
ans.push_back(edge[{i, LC.jump[i][0]}]);
}
}
cout<<ans.size()<<endl;
for(int i : ans) cout<<i<<" "; cout<<endl;
}
