#include<bits/stdc++.h>
using namespace std;
#include<fstream>
#define ll long long
#define vt vector
#define pb push_back
#define fi first
#define se second
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
typedef unsigned long long ull;
#define pii pair<int, int>
#define pll pair<ll, ll>
#include<fstream>
ifstream fin("disrupt.in");
ofstream fout("disrupt.out");
const ll mod = 1e9 + 7;
const int mxn = 1e5, mxm = 5e4, mxlg = 17;
const int inf = 1e9 + 3;
int n, m, k;
vt<pii>adj[mxn + 1];
int cnt[mxn + 1];
set<int>val[mxn + 1];
int up[mxn + 1][17], d[mxn + 1];
vt<int>Lca[mxn + 1];
vt<int>res;
void dfs(int s, int pre){
for(auto i: adj[s]){
if(i.fi == pre)continue;
d[i.fi] = d[s] + 1; up[i.fi][0] = s;
dfs(i.fi, s);
}
}
int lca(int a, int b){
if(d[a] < d[b])swap(a, b);
int k = d[a] - d[b];
forr(i, 0, mxlg){
if(k & (1 << i)){
a = up[a][i];
}
}
if(a == b)return(a);
dorr(i, mxlg - 1, 0){
if(up[a][i] != up[b][i]){
a = up[a][i]; b = up[b][i];
}
}
return(up[a][0]);
}
void dfs2(int s, int pre){
for(auto i: adj[s]){
int v = i.fi, id = i.se;
if(v == pre)continue;
dfs2(v, s);
if(val[v].size() >= k){
res.pb(id);
}
if(val[s].size() < val[v].size())swap(val[s], val[v]);
for(auto j: val[v]){
val[s].insert(j);
}
}
for(auto i: Lca[s]){
val[s].erase(i);
}
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m >> k;
forr(i, 1, n){
int u, v; cin >> u >> v;
adj[u].pb({v, i}); adj[v].pb({u, i});
}
dfs(1, -1);
forr(i, 1, mxlg){
forr(j, 1, n + 1){
up[j][i] = up[up[j][i - 1]][i - 1];
}
}
forr(i, 0, m){
int s, v; cin >> s >> v;
val[v].insert(i);
forr(j, 1, s){
int x; cin >> x;
val[x].insert(i);
v = lca(v, x);
}
Lca[v].pb(i);
}
dfs2(1, -1);
cout << res.size() << "\n";
sort(res.begin(), res.end());
for(int i = 0 ; i < res.size(); i++)cout << res[i] << ' ';
}
