#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 47
#endif
constexpr int N = 1e5;
vector<array<int, 2>> g[N];
int par[N], lvl[N], tin[N], tout[N];
int timer = 0;
void dfs(int u, int p) {
tin[u] = timer++;
for (auto [v, w] : g[u]) {
if (v != p) {
par[v] = u;
lvl[v] = lvl[u] + 1;
dfs(v, u);
}
}
tout[u] = timer - 1;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, k, q, e;
cin >> n >> k >> q >> e;
vector<int> a(n - 1), b(n - 1), w(n - 1);
for (int i = 0; i < n - 1; i++) {
cin >> a[i] >> b[i] >> w[i];
a[i]--; b[i]--;
g[a[i]].push_back({b[i], w[i]});
g[b[i]].push_back({a[i], w[i]});
}
vector<int> s(k);
for (int i = 0; i < k; i++) {
cin >> s[i];
}
e--;
dfs(e, -1);
while (q--) {
int i, r;
cin >> i >> r;
i--; r--;
int u = a[i], v = b[i];
if (lvl[u] > lvl[v]) {
swap(u, v);
}
if (tin[v] <= r && r <= tout[v]) {
cout << "oo\n";
} else {
cout << "escaped\n";
}
}
return 0;
}
