#include<bits/stdc++.h>
using namespace std;
/*for ordered_set
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<pair<int,int>, null_type,less<pair<int,int>>, rb_tree_tag,tree_order_statistics_node_update>
*/
const long long INFll = (long long) 1e18 + 10;
const int INFii = (int) 1e9 + 10;
typedef long long ll;
typedef int ii;
typedef long double dbl;
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
#define maxn 110000
ii n, m, k, cnt[maxn], bit[maxn];
vector<pair<ii,ii>> edg, g[maxn];
ii tin[maxn], tout[maxn], timer = 1;
void att(ii pos, ii val) {
for(ii i = pos; i <= n; i+= i&-i) {
bit[i]+= val;
}
}
ii qr(ii pos) {
ii val = 0;
for(ii i = pos; i > 0; i-= i&-i) {
val+= bit[i];
}
return val;
}
void dfst(ii u, ii ant, ii id) {
//.fr = pai .sc = filho
if(u != 1 && edg[id].fr == u) swap(edg[id].fr,edg[id].sc);
tin[u] = timer++;
for(auto V : g[u]) {
ii v = V.fr;
ii id1 = V.sc;
if(v == ant) continue;
dfst(v,u,id1);
}
tout[u] = timer-1;
}
void solve() {
cin >> n >> m >> k;
for(ii i = 0; i < n-1; i++) {
ii a, b;
cin >> a >> b;
g[a].pb(mp(b,i));
g[b].pb(mp(a,i));
edg.pb(mp(a,b));
}
dfst(1,0,0);
if(n <= 10000 && m <= 2000) {
for(ii i = 0; i < m; i++) {
ii s; cin >> s;
vector<ii> v;
for(ii j = 0; j < s; j++) {
ii u; cin >> u;
v.pb(u);
att(tin[u],+1);
}
for(ii i = 0; i < n-1; i++) {
ii u = edg[i].fr;
ii v = edg[i].sc;
ii sum = qr(tout[v]) - qr(tin[v]-1);
if(sum != 0 && sum-s != 0) cnt[i]++;
}
for(auto u : v) att(tin[u],-1);
}
}
else {
for(ii i = 0; i < m; i++) {
ii s; cin >> s;
vector<ii> v;
ii mn = n+1;
ii mx = 0;
for(ii j = 0; j < s; j++) {
ii u; cin >> u;
mn = min(mn,tin[u]);
mx = max(mx,tin[u]);
}
att(mn,+1);
att(mx,-1);
}
for(ii i = 0; i < n-1; i++) {
ii u = edg[i].fr;
ii v = edg[i].sc;
cnt[i] = qr(tin[u]);
}
}
vector<ii> ans;
for(ii i = 0; i < n-1; i++) {
if(cnt[i] >= k) ans.pb(i+1);
}
cout << ans.size() << endl;
for(auto x : ans) cout << x << " ";
cout << endl;
}
int main() {
ios::sync_with_stdio(false); cin.tie(0);
// freopen("in.in", "r", stdin);
//freopen("out.out", "w", stdout);
ii tt = 1;
// cin >> tt;
while(tt--) solve();
}
