#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvl = vector<vll>;
using pll = pair<ll,ll>;
using vpl = vector<pll>;
using vvp = vector<vpl>;
#define f first
#define s second
#define pb push_back
#define all(v) v.begin(),v.end()
vll ans, sz, dt;
vvp g;
ll k;
vvl pr;
void dfs(ll cr){
for(pll i:g[cr]){
if(i.f!=pr[0][cr]){
pr[0][i.f]=cr;
dt[i.f]=dt[cr]+1;
dfs(i.f);
}
}
}
void calc(ll cr){
for(pll i:g[cr]){
if(i.f!=pr[0][cr]){
calc(i.f);
sz[cr]+=sz[i.f];
if(sz[i.f]>=k)ans.pb(i.s);
}
}
}
ll fpr(ll a, ll b){
for(ll h = 19; h >= 0; --h){
if((1<<h) <= b){
a = pr[h][a];
b -= (1<<h);
}
}
return a;
}
ll lca(ll a, ll b){
if(dt[a]>dt[b])swap(a,b);
b = fpr(b, dt[b]-dt[a]);
if(a==b)return a;
for(ll h = 19; h >= 0; --h){
if(pr[h][a] != pr[h][b]){
a = pr[h][a];
b = pr[h][b];
}
}
return pr[0][a];
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(NULL);
ll n, m, a ,b, s;
cin >> n >> m >> k;
g = vvp(n);
for(ll i = 0; i < n-1; ++i){
cin >> a >> b;
a--;b--;
g[a].pb({b,i});
g[b].pb({a,i});
}
pr = vvl(20, vll(n));
dt = sz = vll(n);
dfs(0);
for(ll h = 1; h < 20; ++h){
for(ll i = 0; i < n; ++i){
pr[h][i] = pr[h-1][pr[h-1][i]];
}
}
for(ll i = 0; i < m; ++i){
cin >> s;
cin >> a >> b;
a--;b--;
ll c = lca(a, b);
sz[a]++;
sz[b]++;
sz[c]-=2;
}
calc(0);
cout << ans.size() << "\n";
for(ll i:ans)cout << i+1 << " ";
}
