#include <bits/stdc++.h>
using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> vii;
typedef long long ll;
int a=1;
int k=1;
vi euler;
vector<vector<vii>> G;
vi path_to_par;
void dfs(int u, int p){
euler.push_back(u);
for(int i=0; i<G[u].size(); i++){
if(G[u][i].first==p){
path_to_par[u]=G[u][i].second;
continue;
}
dfs(G[u][i].first, u);
}
euler.push_back(p);
}
int main() {
int n, m, K;
cin>>n>>m>>K;
G.resize(n);
path_to_par.resize(n);
for(int i=0; i<n-1; i++){
int c, b;
cin>>c>>b;
G[c-1].push_back({b-1, i+1});
G[b-1].push_back({c-1, i+1});
}
//root from 0.
dfs(0, 0);
//find first and last time everything appears
vi f(n, -1);
vi l(n);
for(int i=0; i<euler.size(); i++){
if(f[euler[i]]==-1) f[euler[i]]=i;
l[euler[i]]=i;
}
vvi S(m);
for(int i=0; i<m; i++){
int s;
cin>>s;
for(int j=0; j<s; j++){
int a;
cin>>a;
S[i].push_back(a-1);
}
}
vvi SS(m);
for(int i=0; i<m; i++){
for(int j=0; j<S[i].size(); j++){
SS[i].push_back(f[S[i][j]]);
}
sort(SS[i].begin(), SS[i].end());
}
vi nodes;
for(int i=1; i<n; i++){
int count=0;
for(int j=0; j<m; j++){
if(SS[j][0]>=f[i] && SS[j][SS[j].size()-1]<=l[i]) continue;
if(SS[j][0]>l[i] || SS[j][SS[j].size()-1]<f[i]) continue;
int b=0, c=SS[j].size()-1;
while(b+1<c){
int d=(b+c)/2;
if(SS[j][d]>=f[i]) c=d;
else b=d;
}
if(SS[j][c]<=l[i]) count++;
//find the first index with SS[j][t]>=f[i]
}
if(count>=K) nodes.push_back(i);
}
cout<<nodes.size()<<"\n";
vi y;
for(int i=0; i<nodes.size(); i++){
y.push_back(path_to_par[nodes[i]]);
}
sort(y.begin(), y.end());
for(int i=0; i<y.size(); i++) cout<<y[i]<<" ";
return 0;
}
