#include "bits/stdc++.h"
#define sz(x) (int)size(x)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const char nl = '\n';
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3f;
const int LOG = 20;
int32_t main() {
ios::sync_with_stdio(0), cin.tie(0);
int n, m, k; cin >> n >> m >> k;
vector<vector<int>> adj(n + 1);
vector<pii> edg;
for (int i = 0; i < n - 1; i++) {
int a, b; cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
edg.push_back({a, b});
}
vector<int> pai(n + 1), prof(n + 1);
auto pre = [&](auto pre, int x) -> void {
for (int k : adj[x]) {
if (k == pai[x]) continue;
pai[k] = x;
prof[k] = prof[x] + 1;
pre(pre, k);
}
}; pre(pre, 1);
vector up(n + 1, vector<int>(LOG, -1));
for (int i = 2; i <= n; i++)
up[i][0] = pai[i];
for (int k = 1; k < LOG; k++)
for (int i = 1; i <= n; i++)
if (up[i][k - 1] != -1)
up[i][k] = up[up[i][k - 1]][k - 1];
auto lift = [&](int x, int k) -> int {
for (int i = 0; i < LOG; i++)
if (x != -1) if ((k >> i) & 1)
x = up[x][i];
return x;
};
auto subtree = [&](int a, int b) -> bool { // b na subtree de a
if (prof[b] < prof[a]) return false;
b = lift(b, prof[b] - prof[a]);
return a == b;
};
vector<vector<int>> hood(m);
for (int i = 0; i < m; i++) {
int s; cin >> s;
hood[i].resize(s);
for (auto &x : hood[i]) cin >> x;
}
vector<int> ans;
for (int i = 0; i < m; i++) {
auto [a, b] = edg[i];
int x = (prof[a] > prof[b] ? a : b);
int cnt = 0;
for (int j = 0; j < m; j++) {
int sum = 0;
for (int k : hood[j])
if (subtree(x, k))
sum++;
if (sum != 0 && sum != sz(hood[j]))
cnt++;
}
if (cnt >= k)
ans.push_back(i + 1);
}
cout << sz(ans) << nl;
for (int x : ans) cout << x << ' ';
return 0;
}
