#include<bits/stdc++.h>
//#define int long long
#define pii pair<int,ll>
#define fi first
#define se second
/*#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")*/
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ldb = long double;
const ll N = (int)1e9 + 1;
const int maxN = (int)2e5 + 1;
const int mod = 1e9 + 7;
//const int mod = 998244353;
const int infty = 2e9 + 7;
const int base = (int)4e5;
void InputFile()
{
//freopen("scrivener.inp","r",stdin);
//freopen("scrivener.out","w",stdout);
//freopen("test.out","r",stdin);
}
void FastInput()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
}
int n,m,k;
vector<vector<int>> adj;
int x[maxN],y[maxN];
void Read()
{
cin >> n >> m >> k;
adj.resize(n+1);
for(int i = 1;i < n;i++)
{
cin >> x[i] >> y[i];
adj[x[i]].push_back(i);
adj[y[i]].push_back(i);
}
}
int TimeDFS = 0;
int sta[maxN];
int of_edge[maxN];
int anc[25][maxN];
int depth[maxN];
int dp[maxN];
void PreDFS(int u,int p)
{
sta[u] = ++TimeDFS;
for(int i : adj[u])
{
int v = x[i] + y[i] - u;
if(v == p) continue;
of_edge[v] = i;
depth[v] = depth[u] + 1;
anc[0][v] = u;
for(int i = 1;(1 << i) <= n;i++)
{
anc[i][v] = anc[i-1][anc[i-1][v]];
}
PreDFS(v,u);
}
}
int LCA(int u,int v)
{
if(depth[u] < depth[v]) swap(u,v);
int k = (depth[u] - depth[v]);
for(int i = log2(n);i >= 0;i--)
{
if(k & (1 << i))
{
u = anc[i][u];
k ^= (1 << i);
}
}
if(u == v) return u;
for(int i = log2(n);i >= 0;i--)
{
if(anc[i][u] != anc[i][v])
{
u = anc[i][u];
v = anc[i][v];
}
}
return anc[0][u];
}
bool FA(int i,int j)
{
return sta[i] < sta[j];
}
void DFS(int u,int p)
{
for(int i : adj[u])
{
int v = x[i] + y[i] - u;
if(v == p) continue;
DFS(v,u);
dp[u] += dp[v];
}
}
void Solve()
{
PreDFS(1,0);
while(m--)
{
int sz;
cin >> sz;
vector<int> chosen;
chosen.resize(sz);
for(int i = 0;i < sz;i++)
{
cin >> chosen[i];
dp[chosen[i]]++;
}
sort(chosen.begin(),chosen.end(),FA);
for(int i = 0;i < sz;i++)
{
int nxt = (i + 1) % sz;
dp[LCA(chosen[i],chosen[nxt])]--;
}
}
DFS(1,0);
vector<int> res;
for(int i = 2;i <= n;i++)
{
if(dp[i] >= k)
{
res.push_back(of_edge[i]);
}
}
//cout << of_edge[6];return;
sort(res.begin(),res.end());
cout << res.size() <<'\n';
for(int i : res)
cout << i <<' ';
}
void Debug()
{
}
int32_t main()
{
FastInput();
//InputFile();
//int sub_type;
//cin >> sub_type;
//Sieve();
//Prepare();
int test;
//cin >> test;
test = 1;
while(test--)
//for(int prc = 1; prc <= test; prc++)
{
Read();
Solve();
//Debug();
}
}
