#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
x += k;
x %= mod;
if(x < 0) x += mod;
}
void del(int &x, int k)
{
x -= k;
x %= mod;
if(x < 0) x += mod;
}
int n,q,k;
vi adj[maxn],ke[maxn];
int pos[maxn],tail[maxn],h[maxn];
int par[maxn][20];
int cnt;
void dfs(int u)
{
pos[u] = ++cnt;
for(int v : ke[u]) if(v != par[u][0])
{
h[v] = h[u] + 1;
par[v][0] = u;
fo(i,1,19) par[v][i] = par[par[v][i - 1]][i - 1];
dfs(v);
}
tail[u] = cnt;
}
int lca(int u, int v)
{
if (h[u] < h[v])
swap(u, v);
int del = h[u] - h[v];
fod(i, 19, 0) if (bit(del, i)) u = par[u][i];
if (u == v)
return u;
fod(i, 19, 0) if (par[u][i] != par[v][i]) u = par[u][i], v = par[v][i];
return par[u][0];
}
int p[maxn];
void dfs1(int u,int parent = 0)
{
for(int v : adj[u]) if(v != parent)
{
p[v]++;
p[u]--;
dfs1(v,u);
}
}
void dfs2(int u,int parent = 0)
{
for(int v : ke[u]) if(v != parent)
{
dfs2(v,u);
p[u] += p[v];
}
}
pii edge[maxn];
main()
{
#define name "TASK"
if (fopen(name ".inp", "r"))
{
freopen(name ".inp", "r", stdin);
freopen(name ".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> q >> k;
fo(i,1,n - 1)
{
int u,v;
cin >> u >> v;
ke[u].pb(v);
ke[v].pb(u);
edge[i] = {u,v};
}
dfs(1);
while(q--)
{
int m;
cin >> m;
vi arr(m);
for(int &it : arr) cin >> it;
sort(all(arr),[](int a,int b)
{
return pos[a] < pos[b];
});
fo(i,1,m - 1) arr.pb(lca(arr[i],arr[i - 1]));
sort(all(arr));
arr.erase(unique(all(arr)),arr.end());
stack<int> st;
sort(all(arr),[](int a,int b)
{
return pos[a] < pos[b];
});
for(int it : arr)
{
if(st.empty()) st.push(it);
else
{
while(ss(st) and tail[st.top()] < pos[it]) st.pop();
adj[st.top()].pb(it);
st.push(it);
}
}
dfs1(arr[0]);
for(int it : arr) adj[it].clear();
}
dfs2(1);
vi res;
fo(i,1,n - 1)
{
auto [u,v] = edge[i];
if(pos[u] < pos[v]) swap(u,v);
if(p[u] >= k) res.pb(i);
}
cout << ss(res);en;
for(int it : res) cout << it << ' ';
}
