#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e15;
const int MAXN = 1e5 + 5;
struct Edge { int to, weight, id; };
vector<Edge> adj[MAXN];
pair<int, int> edges[MAXN];
int tin[MAXN], tout[MAXN], timer;
int up[MAXN][20];
ll dist[MAXN], close_shop[MAXN], best[MAXN][20];
bool has_shop[MAXN];
int N, S, Q, E;
void dfs_pre(int u, int p, ll d) {
tin[u] = ++timer;
up[u][0] = p;
dist[u] = d;
close_shop[u] = has_shop[u] ? d : INF;
for (auto &e : adj[u]) {
if (e.to == p) continue;
dfs_pre(e.to, u, d + e.weight);
close_shop[u] = min(close_shop[u], close_shop[e.to]);
}
best[u][0] = (close_shop[u] == INF) ? INF : (close_shop[u] - 2 * dist[u]);
tout[u] = timer;
}
bool is_ancestor(int u, int v) {
return tin[u] <= tin[v] && tout[u] >= tout[v];
}
void solve() {
cin >> N >> S >> Q >> E;
for (int i = 1; i < N; ++i) {
int u, v, w; cin >> u >> v >> w;
adj[u].push_back({v, w, i});
adj[v].push_back({u, w, i});
edges[i] = {u, v};
}
for (int i = 0; i < S; ++i) { int s; cin >> s; has_shop[s] = true; }
dfs_pre(E, E, 0);
for (int j = 1; j < 20; ++j) {
for (int i = 1; i <= N; ++i) {
up[i][j] = up[up[i][j - 1]][j - 1];
best[i][j] = min(best[i][j - 1], best[up[i][j - 1]][j - 1]);
}
}
while (Q--) {
int idx, R; cin >> idx >> R;
int u = edges[idx].first, v = edges[idx].second;
int child = (is_ancestor(u, v)) ? v : u;
if (!is_ancestor(child, R)) {
cout << "escaped\n";
} else {
ll res = INF;
int curr = R;
for (int j = 19; j >= 0; --j) {
if (is_ancestor(child, up[curr][j])) {
res = min(res, best[curr][j]);
curr = up[curr][j];
}
}
res = min(res, best[curr][0]);
if (res >= INF / 2) cout << "oo\n";
else cout << res + dist[R] << "\n";
}
}
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
#define TASK "TEST"
if (fopen(TASK".INP", "r"))
{
freopen(TASK".INP", "r", stdin);
freopen(TASK".ans", "w", stdout);
}
solve();
return 0;
}
