#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using db = long double; // or double if tight TL
using str = string;
using pi = pair<int,int>;
#define mp make_pair
#define f first
#define s second
#define tcT template<class T
tcT> using V = vector<T>;
tcT, size_t SZ> using AR = array<T,SZ>;
using vi = V<int>;
using vb = V<bool>;
using vpi = V<pi>;
#define sz(x) int((x).size())
#define all(x) begin(x), end(x)
#define sor(x) sort(all(x))
#define rsz resize
#define pb push_back
#define ft front()
#define bk back()
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define rep(a) F0R(_,a)
#define each(a,x) for (auto& a: x)
const int MOD = 1e9+7;
const int SZ = (1<<18);
tcT> bool ckmin(T& a, const T& b) {
return b < a ? a = b, 1 : 0; } // set a = min(a,b)
tcT> bool ckmax(T& a, const T& b) {
return a < b ? a = b, 1 : 0; } // set a = max(a,b)
tcT, int SZ> struct LazySeg{
const T ID{}; T cmb(T a, T b) { return a+b; }
T seg[2*SZ], lazy[2*SZ];
LazySeg() { F0R(i,2*SZ) seg[i] = lazy[i] = ID; }
void push(int ind, int L, int R) {
seg[ind] += (R-L+1)*lazy[ind];
if (L != R) F0R(i,2) lazy[2*ind+i] += lazy[ind];
lazy[ind] = 0;
}
void pull(int ind){seg[ind]=cmb(seg[2*ind],seg[2*ind+1]);}
void build() { ROF(i,1,SZ) pull(i); }
void upd(int lo,int hi,T inc,int ind=1,int L=0, int R=SZ-1) {
push(ind,L,R); if (hi < L || R < lo) return;
if (lo <= L && R <= hi) {
lazy[ind] = inc; push(ind,L,R); return; }
int M = (L+R)/2; upd(lo,hi,inc,2*ind,L,M);
upd(lo,hi,inc,2*ind+1,M+1,R); pull(ind);
}
T query(int lo, int hi, int ind=1, int L=0, int R=SZ-1) {
push(ind,L,R); if (lo > R || L > hi) return ID;
if (lo <= L && R <= hi) return seg[ind];
int M = (L+R)/2; return cmb(query(lo,hi,2*ind,L,M),
query(lo,hi,2*ind+1,M+1,R));
}
};
struct HLD{
int N; vector<int> adj[SZ];
int par[SZ], root[SZ], depth[SZ], sz[SZ], ti;
int pos[SZ]; vector<int> rpos;
void ae(int x, int y) { adj[x].pb(y), adj[y].pb(x); }
void dfsSz(int x) {
sz[x] = 1;
each(y,adj[x]) {
par[y] = x; depth[y] = depth[x]+1;
adj[y].erase(find(all(adj[y]),x));
dfsSz(y); sz[x] += sz[y];
if (sz[y] > sz[adj[x][0]]) swap(y,adj[x][0]);
}
}
void dfsHld(int x) {
pos[x] = ti++; rpos.pb(x);
each(y,adj[x]) {
root[y] = (y == adj[x][0] ? root[x] : y);
dfsHld(y); }
}
void init(int _N, int R = 0) { N = _N;
par[R] = depth[R] = ti = 0; dfsSz(R);
root[R] = R; dfsHld(R);
}
int lca(int x, int y) {
for (; root[x] != root[y]; y = par[root[y]])
if (depth[root[x]] > depth[root[y]]) swap(x,y);
return depth[x] < depth[y] ? x : y;
}
LazySeg<ll,SZ> tree; //segtree for sum
template <class BinaryOp>
void processPath(int x, int y, BinaryOp op) {
for (; root[x] != root[y]; y = par[root[y]]) {
if (depth[root[x]] > depth[root[y]]) swap(x,y);
op(pos[root[y]],pos[y]); }
if (depth[x] > depth[y]) swap(x,y);
op(pos[x]+1,pos[y]);
}
void modifyPath(int x, int y, int v) {
processPath(x,y,[this,&v](int l, int r){ tree.upd(l,r,v); });
}
ll queryPath(int x, int y) {
ll res = 0; processPath(x,y,[this,&res](int l, int r) {
res += tree.query(l,r); });
return res;
}
void modifySubtree(int x, int v){
tree.upd(pos[x],pos[x]+sz[x]-1,v); }
}hld;
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int N,M,K; cin >> N >> M >> K;
vector<pair<int,int>> edges;
for(int i = 1;i<=N-1;++i){
int a,b; cin >> a >> b;
hld.adj[a].push_back(b); hld.adj[b].push_back(a);
edges.push_back({a,b});
}
hld.init(N+1,1);
for(int i = 1;i<=M;++i){
int x; cin >> x;
int last; cin >> last;
for(int j = 2;j<=x;++j){
int u; cin >> u;
hld.modifyPath(last,u,1);
last = u;
}
}
int ans = 0;
vector<int> out;
for(int i = 0;i<N-1;++i){
if(hld.queryPath(edges[i].f,edges[i].s) >= K){
++ans;
out.push_back(i);
}
}
cout << ans << "\n";
for(int i = 0;i<out.size();++i){
if(i != out.size()-1) cout << out[i]+1 << " ";
else cout << out[i]+1 << "\n";
}
return 0;
}
