#include <bits/stdc++.h>
using namespace std;
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
#define pb push_back
#define ll long long
#define f first
#define s second
#define sz(v) int(v.size())
#define all(v) v.begin(),v.end()
int mod = 1e9 + 7;
const int N = 1e5 + 100;
const ll inf = 2e18;
vector <int> g[N];
void solve(){
int n,m,k;
cin >> n >> m >> k;
vector <array<int,3>> e;
for(int i = 1; i < n; i++){
int u,v;
cin >> u >> v;
e.pb({u,v,i});
}
for(int i = 1; i <= m; i++){
int d;
cin >> d;
while(d--){
int x;
cin >> x;
g[i].pb(x);
}
}
vector <int> ans;
for(auto [u,v,i] : e){
int cnt1 = 0;
for(int j = 1; j <= m; j++){
bool f = 0;
for(auto to : g[j]){
if(to == i){
f = 1;
break;
}
}
cnt1 += f;
if(cnt1 >= k) break;
}
if(cnt1 >= k) ans.pb(i);
}
cout << ans.size() << '\n';
for(auto to : ans) cout << to << ' ';
}
signed main(){
//freopen("time.in", "r", stdin);
//freopen("time.out", "w", stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int t1 = 1;
while(t1--){
solve();
}
}
