//Make CSP great again
//Vengeance
#include <bits/stdc++.h>
#define TASK "TESTCODE"
#define Log2(x) 31 - __builtin_clz(x)
using namespace std;
const int N = 1e5, cbit = 16;
int dp[N + 1], tin[N + 1], tout[N + 1], timer, n, m, k, x[N], y[N], f[N + 1][cbit + 1], depth[N + 1];
vector<int> adj[N + 1], res, city;
void read()
{
cin >> n >> m >> k;
for (int i = 1; i < n; ++ i)
{
cin >> x[i] >> y[i];
adj[x[i]].push_back(i);
adj[y[i]].push_back(i);
}
}
void preDFS(int u, int p)
{
tin[u] = ++timer;
for (int i : adj[u])
{
int v = x[i] ^ u ^ y[i];
if (v == p)
{
continue;
}
depth[v] = depth[u] + 1;
f[v][0] = u;
for (int j = 1; j <= cbit; ++ j)
{
f[v][i] = f[f[v][j - 1]][j - 1];
}
preDFS(v, u);
}
tout[u] = ++timer;
}
int LCA(int u, int v)
{
if (depth[u] > depth[v])
{
swap(u, v);
}
int x = depth[v] - depth[u];
for (int i = cbit; i >= 0; -- i)
{
if ((x >> i) & 1)
{
v = f[v][i];
}
}
if (u == v)
{
return u;
}
for (int i = cbit; i >= 0; -- i)
{
if (f[u][i] != f[v][i])
{
u = f[u][i];
v = f[v][i];
}
}
return f[u][0];
}
void ReadQuery()
{
int s;
cin >> s;
city.clear();
while(s--)
{
int u;
cin >> u;
city.push_back(u);
}
sort(city.begin(), city.end(), [&] (const int &u, const int &v)
{
return tin[u] < tin[v];
});
vector<int> t;
for (int i = 1; i < city.size(); ++ i)
{
t.push_back(LCA(city[i], city[i - 1]));
}
move(t.begin(), t.end(), back_inserter(city));
sort(city.begin(), city.end(), [&] (const int &u, const int &v)
{
return tin[u] < tin[v];
});
city.erase(unique(city.begin(), city.end()), city.end());
}
void DnC()
{
stack<int> st;
for (int v : city)
{
while(!st.empty())
{
int u = st.top();
if (tin[v] <= tout[u])
{
--dp[u];
++dp[v];
break;
}
else
{
st.pop();
}
}
st.push(v);
}
}
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];
if (dp[v] >= k)
{
res.push_back(i);
}
}
}
void solve()
{
preDFS(1, 0);
while(m--)
{
ReadQuery();
DnC();
}
DFS(1, 0);
cout << res.size() << '\n';
for (int i : res)
{
cout << i << ' ';
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
if (fopen(TASK".INP", "r"))
{
freopen(TASK".INP", "r", stdin);
//freopen(TASK".OUT", "w", stdout);
}
int t = 1;
bool typetest = false;
if (typetest)
{
cin >> t;
}
for (int __ = 1; __ <= t; ++ __)
{
//cout << "Case " << __ << ": ";
read();
solve();
}
}
