#include <bits/stdc++.h>
using namespace std;
using ll = long long;
//#define int ll
using P = pair<int, int>;
#define all(x) x.begin(), x.end()
#define rep(i, l, n) for (int i = l; i < (n); ++i)
#define sz(x) (int)x.size()
const char nl = '\n';
const int mod = 998244353;
const int NMAX = 1e5+10;
struct edge{
int v, w, id;
};
P E[NMAX];
vector<edge> g[NMAX];
int tin[NMAX], tout[NMAX];
int t = 0;
void dfs(int nd = 1, int p = -1) {
tin[nd] = t++;
for (auto ch: g[nd]) {
if (ch.v == p)continue;
E[ch.id] = {nd, ch.v};
dfs(ch.v, nd);
}
tout[nd] = t;
}
bool f(int l, int r, int x) {
if (l <= x && r <= x)return 1;
return 0;
}
void solve() {
int n, s, q, e;
cin >> n >> s >> q >> e;
rep(i, 1, n) {
int u, v, w; cin >> u >> v >> w;
g[u].push_back({v, w, i});
g[v].push_back({u, w, i});
}
rep(i, 0, s) {
int c; cin >> c;
}
while (q--) {
int I, R; cin >> I >> R;
int v = E[I].second;
int a = f(tin[v], tout[v], tin[e]);
int b = f(tin[v], tout[v], tin[R]);
if (a^b)cout << 0 << nl;
else cout << "escaped\n";
}
}
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
solve();
return 0;
}
