#include <bits/stdc++.h>
using namespace std;
const int LOG = 18;
struct Lca {
int n;
vector<int> dep;
vector<vector<int>> up;
Lca(vector<int> par, vector<int> dep) : n(par.size()), dep(dep) {
up.assign(n, vector<int>(LOG));
for (int i = 0; i < n; ++i) {
up[i][0] = par[i];
}
for (int i = 1; i < LOG; ++i) {
for (int j = 0; j < n; ++j) {
up[j][i] = up[up[j][i-1]][i-1];
}
}
}
int lift(int v, int k) {
for (int i = LOG-1; i >= 0; --i) {
if (k & (1 << i)) {
v = up[v][i];
k -= 1 << i;
}
}
return v;
}
int lca(int a, int b) {
if (dep[a] > dep[b]) swap(a, b);
b = lift(b, dep[b] - dep[a]);
for (int i = LOG-1; i >= 0; --i) {
if (up[a][i] != up[b][i]) {
a = up[a][i];
b = up[b][i];
}
}
if (a == b) return a;
return up[a][0];
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n; cin >> n;
int m; cin >> m;
int k; cin >> k;
vector<array<int, 2>> e;
vector<vector<int>> adj(n);
for (int i = 0, a, b; i < n-1; ++i) {
cin >> a >> b; --a; --b;
e.push_back({a, b});
adj[a].push_back(b);
adj[b].push_back(a);
}
vector<int> par(n), dep(n);
auto dfs = [&](auto&& self, int v) -> void {
for (int u : adj[v]) {
if (u == par[v]) continue;
dep[u] = dep[v] + 1;
par[u] = v;
self(self, u);
}
};
dfs(dfs, 0);
Lca lca(par, dep);
vector<vector<array<int, 2>>> actions(n);
for (int i = 0; i < m; ++i) {
int s; cin >> s;
int l; cin >> l; --l;
for (int j = 1, a; j < s; ++j) {
cin >> a; --a;
int nl = lca.lca(l, a);
actions[a].push_back({i, 1});
actions[l].push_back({i, 1});
actions[nl].push_back({i, 0});
l = nl;
}
}
vector<int> cnt(n);
auto solve = [&](auto&& self, int v) -> set<int> {
set<int> s;
for (int u : adj[v]) {
if (u == par[v]) continue;
auto ss = self(self, u);
if (ss.size() > s.size()) swap(s, ss);
for (int i : ss) s.insert(i);
}
for (auto [a, b] : actions[v]) {
if (b == 1) s.insert(a);
else {
auto it = s.find(a);
if (it != s.end()) {
s.erase(it);
}
}
}
cnt[v] = s.size();
return s;
};
solve(solve, 0);
vector<int> ans;
for (int i = 0; i < n-1; ++i) {
auto [a, b] = e[i];
if (par[a] == b && cnt[a] >= k) ans.push_back(i+1);
else if (par[b] == a && cnt[b] >= k) ans.push_back(i+1);
}
cout << ans.size() << "\n";
for (int i : ans) {
cout << i << " ";
}
cout << "\n";
}
