#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int ll
vector<pair<int, ll>> adj[100005];
int height[100005], jmp[100005][20];
int tin[100005], timer = 1;
int rev[100005];
ll best[100005];
struct querystr {
int a, b, c;
};
//~ void prop(int node) {
//~ for (auto a : adj[node]) {
//~ if (height[a.first] < height[node]) continue;
//~ if (best[a.first] > best[node] + a.second) {
//~ best[a.first] = best[node] + a.second;
//~ prop(a.first);
//~ }
//~ }
//~ }
void dfs(int node) {
tin[node] = timer++;
rev[tin[node]] = node;
for (int i = 1; i < 20; i++) {
jmp[node][i] = jmp[jmp[node][i-1]][i-1];
}
for (auto nxt : adj[node]) {
if (height[nxt.first]) continue;
height[nxt.first] = height[node] + 1;
jmp[nxt.first][0] = node;
dfs(nxt.first);
}
}
int lca(int a, int b) {
if (height[a] > height[b]) swap(a, b);
for (int i = 19; i >= 0; i--) {
if (height[jmp[b][i]] >= height[a]) b = jmp[b][i];
}
if (a == b) return a;
for (int i = 19; i >= 0; i--) {
if (jmp[a][i] != jmp[b][i]) {
a = jmp[a][i]; b = jmp[b][i];
}
}
return jmp[a][0];
}
ll val[100005];
ll sump[100005];
bool shop[100005];
ll mintoshop[100005];
void precalc(int node) {
for (auto nxt : adj[node]) {
if (height[nxt.first] < height[node]) continue;
sump[nxt.first] = sump[node] + nxt.second;
precalc(nxt.first);
}
if (shop[node]) {
mintoshop[node] = sump[node];
} else {
mintoshop[node] = LLONG_MAX/2;
for (auto nxt : adj[node]) {
if (height[nxt.first] < height[node]) continue;
mintoshop[node] = min(mintoshop[node], mintoshop[nxt.first]);
}
}
}
void build(int node) {
for (auto nxt : adj[node]) {
if (height[nxt.first] < height[node]) continue;
build(nxt.first);
}
if (shop[node]) {
val[node] = -1 * sump[node];
} else {
val[node] = LLONG_MAX/2;
if (mintoshop[node] < LLONG_MAX/3) {
val[node] = -2 * sump[node] + mintoshop[node];
}
}
//~ cout << node << " " << val[node] << endl;
}
ll minjmp[100005][20];
void lcaagain(int node) {
minjmp[node][0] = min(val[node], val[jmp[node][0]]);
for (int i = 1; i < 20; i++) {
minjmp[node][i] = min(minjmp[node][i-1], minjmp[jmp[node][i-1]][i-1]);
//~ cout << node << " " << i << " " << minjmp[node][i] << endl;
}
for (auto nxt : adj[node]) {
if (height[nxt.first] < height[node]) continue;
lcaagain(nxt.first);
}
}
struct edge {
int a, b; ll c;
};
vector<edge> edges;
int32_t main() {
int n, s, e, q; cin >> n >> s >> q >> e;
for (int i = 0; i < n-1; i++) {
int a, b; ll c; cin >> a >> b >> c;
edges.push_back({a, b, c});
adj[a].emplace_back(b, c);
adj[b].emplace_back(a, c);
}
vector<int> shops;
for (int i = 0; i < s; i++) {
int a; cin >> a;
shop[a] = true;
shops.push_back(a);
}
height[e] = 1;
jmp[e][0] = e;
dfs(e);
vector<querystr> todo;
vector<int> answer(q);
precalc(e);
build(e);
lcaagain(e);
for (int i = 0; i < q; i++) {
int rd, loc; cin >> rd >> loc;
rd--;
int greaterd = (height[edges[rd].a] > height[edges[rd].b] ? edges[rd].a : edges[rd].b);
if (lca(loc, greaterd) == greaterd) {
if (shop[loc]) {
cout << "0\n";
continue;
}
ll minval = val[loc];
int temploc = loc;
for (int i = 19; i >= 0; i--) {
// loc -> greaterd
if (height[jmp[temploc][i]] >= height[greaterd]) {
minval = min(minval, minjmp[temploc][i]);
temploc = jmp[temploc][i];
}
}
if (minval >= LLONG_MAX/3) cout << "oo\n";
else cout << minval + sump[loc] << "\n";
//~ todo.push_back({greaterd, i, loc});
//~ priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
//~ pq.push({0, loc});
//~ vector<ll> dist(100005, LLONG_MAX/2);
//~ dist[loc] = 0;
//~ bool done = false;
//~ while (!pq.empty()) {
//~ auto cur = pq.top(); pq.pop();
//~ if (cur.first != dist[cur.second]) continue;
//~ if (shop[cur.second]) {
//~ cout << cur.first << "\n";
//~ done = true;
//~ break;
//~ }
//~ for (auto nxt : adj[cur.second]) {
//~ if (cur.second == greaterd && nxt.first == jmp[cur.second][0]) continue;
//~ if (dist[nxt.first] <= cur.first + nxt.second) continue;
//~ dist[nxt.first] = cur.first + nxt.second;
//~ pq.push({cur.first + nxt.second, nxt.first});
//~ }
//~ }
//~ if (!done) {
//~ cout << "oo\n";
//~ continue;
//~ }
} else cout << "escaped\n";
}
//~ sort(todo.begin(), todo.end(), [](querystr a, querystr b) {
//~ return tin[a.a] > tin[b.a];
//~ });
//~ for (auto a : todo) {
//~ cout << a.first << " " << a.second << endl;
//~ }
//~ int idx = 0;
//~ fill(best, best+100005, LLONG_MAX/2);
//~ for (int i = timer-1; i >= 1; i--) {
//~ // rev[i]
//~ int cur = rev[i];
//~ if (shop[cur]) {
//~ best[cur] = 0;
//~ // check downards
//~ prop(cur);
//~ } else {
//~ best[cur] = LLONG_MAX / 2;
//~ for (auto a : adj[cur]) {
//~ if (height[a.first] < height[cur]) continue;
//~ best[cur] = min(best[cur], a.second + best[a.first]);
//~ }
//~ }
//~ cout << cur << " " << best[cur] << endl;
//~ if (idx < todo.size() && todo[idx].a == cur) {
//~ answer[todo[idx].b] = best[todo[idx].c];
//~ idx++;
//~ }
//~ }
//~ for (auto ans : answer) {
//~ if (ans == -1) cout << "escaped\n";
//~ else if (ans == LLONG_MAX/2) cout << "oo\n";
//~ else cout << ans << "\n";
//~ }
}
