#include <bits/stdc++.h>
using namespace std;
#define task ""
const int MAX = 100010;
int n, s, q, e;
long long INF;
bool shop[MAX];
pair<int, int> edges[MAX];
vector<pair<int, int>> adj[MAX];
int timer, tin[MAX], tout[MAX], h[MAX];
long long dep[MAX], minD[MAX][2];
void preDfs(int u, int p) {
tin[u] = ++timer;
if (shop[u]) minD[u][0] = 0;
for (pair<int, int> &e: adj[u]) if (e.first != p) {
int v = e.first, w = e.second;
dep[v] = dep[u] + w;
h[v] = h[u] + 1;
preDfs(v, u);
if (minD[u][0] >= minD[v][0] + w) {
minD[u][1] = minD[u][0];
minD[u][0] = minD[v][0] + w;
} else minD[u][1] = min(minD[u][1], minD[v][0] + w);
}
tout[u] = timer;
}
long long getD(int u, int v, int w) {
return minD[u][0] == minD[v][0] + w ? minD[u][1] : minD[u][0] - dep[u];
}
long long dp[17][MAX];
int anc[17][MAX];
void dfs(int u, int p) {
for (pair<int, int> &e: adj[u]) if (e.first != p) {
int v = e.first, w = e.second;
dp[0][v] = getD(u, v, w);
anc[0][v] = u;
for (int j = 1; j <= 16; ++j) {
anc[j][v] = anc[j - 1][anc[j - 1][v]];
dp[j][v] = min(dp[j - 1][v], dp[j - 1][anc[j - 1][v]]);
}
dfs(v, u);
}
}
bool isAnc(int u, int v) {
return tin[u] <= tin[v] && tout[v] <= tout[u];
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
cin >> n >> s >> q >> e;
for (int i = 1; i < n; ++i) {
int u, v, w; cin >> u >> v >> w;
edges[i] = make_pair(u, v);
adj[u].push_back(make_pair(v, w));
adj[v].push_back(make_pair(u, w));
}
for (int i = 1; i <= s; ++i) {
int u; cin >> u;
shop[u] = true;
}
memset(minD, 0x3f, sizeof minD); INF = minD[0][0];
preDfs(e, -1);
dfs(e, -1);
while (q--) {
int id, R; cin >> id >> R;
int u = edges[id].first, v = edges[id].second;
if (tin[u] > tin[v]) swap(u, v);
if (isAnc(v, R) == false) {
cout << "escaped\n";
continue;
}
long long ans = minD[R][0];
if (v != R) {
u = R;
for (int j = 0, k = h[R] - h[v]; (1 << j) <= k; ++j) {
if (k >> j & 1) {
ans = min(ans, dep[R] + dp[j][u]);
u = anc[j][u];
}
}
}
if (ans == INF) cout << "oo\n";
else cout << ans << '\n';
}
return 0;
}
