#include<bits/stdc++.h>
using namespace std;
#define debug(n,m) cout<<"["<<#n<<"]->"<<n<<m
#define int long long
#define all(x,off) x.begin()+off,x.end()
#define pb push_back
const int N=1e6+10;
const int inf=9e17;
const int mod=1e9+7;
int n,m,k;
vector<int> g[N];
int in[N],out[N];
int x[N],y[N];
vector<int> ve[2001];
int tim=0;
void dfs(int u,int pa) {
in[u]=++tim;
for (int v : g[u]) {
if (v==pa) continue;
dfs(v,u);
}
out[u]=++tim;
}
int check(int idx) {
int l=x[idx],r=y[idx];
if (in[l]>in[r]&&out[l]<out[r]) swap(l,r);
// debug(l,' ');
// debug(r,'\n');
int cnt=0;
for (int i=1;i<=m;++i) {
int cur=0;
for (int el : ve[i]) {
//if (!el) continue;
if (in[el]>in[l]&&out[el]<out[l]&&in[el]>=in[r]&&out[el]<=out[r]){
++cur;
}
}
if (cur>0&&cur!=ve[i].size()&&ve[i].size()>1) {
++cnt;
// debug(cur,' ');
// debug(i,'\n');
}
}
return cnt;
}
void levi() {
cin>>n>>m>>k;
for (int i=1;i<n;++i ){
cin>>x[i]>>y[i];
g[x[i]].pb(y[i]);
g[y[i]].pb(x[i]);
}
dfs(1,-1);
for (int i=1;i<=m;++i) {
int l;
cin>>l;
ve[i].resize(l);
for (int j=1;j<=l;++j) {
cin>>ve[i][j-1];
}
}
vector<int> v;
for (int i=1;i<n;++i) {
if (check(i)>=k) v.pb(i);
}
cout<<v.size()<<'\n';
for (int id : v) {
cout<<id<<" ";
}
cout<<'\n';
//sus
}
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);int tt=1;//cin>>tt;
while (tt--) levi();
}
/*
*/
