#include <bits/stdc++.h>
#define all(dataStructure) dataStructure.begin(),dataStructure.end()
typedef long long ll;
using namespace std;
namespace std {
template <typename T, int D>
struct _vector : public vector <_vector <T, D - 1>> {
static_assert(D >= 1, "Dimension must be positive!");
template <typename... Args>
_vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
};
// _vector <int, 3> a(n, m, k);: int a[n][m][k].
// _vector <int, 3> a(n, m, k, x);: int a[n][m][k] initialized with x.
template <typename T>
struct _vector <T, 1> : public vector <T> {
_vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
};
}
const int MAX = 1e5 + 3;
const ll MOD[] = {1000000007, 998244353};
int n, m, k;
vector <int> adj[MAX];
int u[MAX], v[MAX];
int cnt[MAX];
int depth[MAX], tin[MAX], tout[MAX], timeDfs;
int pa[MAX][18];
void dfs(int u, int pre) {
depth[u] = depth[pre] + 1;
tin[u] = ++timeDfs;
pa[u][0] = pre;
for (int i = 1; i <= 17; i++) pa[u][i] = pa[pa[u][i - 1]][i - 1];
for (int &v : adj[u]) if (v != pre) dfs(v, u);
tout[u] = timeDfs;
}
int __lca(int u, int v) {
if (depth[u] < depth[v]) swap(u, v);
int dist = depth[u] - depth[v];
while (dist) {
u = pa[u][__builtin_ctz(dist)];
dist -= dist & -dist;
}
if (u == v) {
return u;
} else {
for (int i = 17; i >= 0; i--) {
if (pa[u][i] != pa[v][i]) {
u = pa[u][i];
v = pa[v][i];
}
}
return pa[u][0];
}
}
void reDfs(int u, int pre) {
for (int &v : adj[u]) if (v != pre) {
reDfs(v, u);
cnt[u] += cnt[v];
}
}
void Solve() {
cin >> n >> m >> k;
for (int i = 1; i < n; i++) {
cin >> u[i] >> v[i];
adj[u[i]].push_back(v[i]);
adj[v[i]].push_back(u[i]);
}
dfs(1, 0);
while (m--) {
int sz;
cin >> sz;
vector <int> V(sz);
for (int &x : V) cin >> x;
sort(all(V), [&](const int &i, const int &j) {
return tin[i] < tin[j];
});
for (int i = 0; i < sz; i++) {
cnt[V[i]]++;
cnt[__lca(V[i], V[(i + 1) % sz])]--;
}
}
reDfs(1, 0);
int cntAns = 0;
for (int i = 1; i < n; i++) {
if (depth[u[i]] < depth[v[i]]) swap(u[i], v[i]);
if (cnt[u[i]] >= k) cntAns++;
}
cout << cntAns << '\n';
for (int i = 1; i < n; i++) {
if (cnt[u[i]] >= k) cout << i << ' ';
}
}
int32_t main() {
std::ios_base::sync_with_stdio(0);
std::cin.tie(0); std::cout.tie(0);
#define TASK "TR"
if (fopen(TASK".INP", "r")) {
freopen(TASK".INP", "r", stdin);
freopen(TASK".OUT", "w", stdout);
}
if (fopen("TASK.INP", "r")) {
freopen("TASK.INP", "r", stdin);
freopen("TASK.OUT", "w", stdout);
}
/* int TEST = 1; cin >> TEST; while (TEST--) */ Solve();
cerr << "\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << "s\n";
return 0;
}
