#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
const int MAX = 2e17;
const int N = 1e5;
const int LOG = 17;
int n, s, q, e;
vector< pair<int, int> > g[N + 1];
vector< pair<int, int> > edges;
vector<int> shops;
int is_shop[N+1], up[N+1][LOG+2], depth_sum[N+1];
int depth[N+1], tin[N+1], tout[N+1], range[N+1];
int timer, T;
int euler[N * 2 + 100];
int lg[N*2 + 100], dist_shop[N + 10];
int lst[N*2+100];
void dfs(int v, int par){
tin[v] = timer++;
range[v] = T;
lst[v] = T;
euler[T++] = v;
up[v][0] = par;
for(int j = 1;j <= LOG; j++){
up[v][j] = up[up[v][j-1]][j-1];
}
int distance = MAX;
for(auto [to, w] : g[v]){
if(to == par) continue;
depth[to] = depth[v] + 1;
depth_sum[to] = depth_sum[v] + w;
dfs(to, v);
lst[v] = T;
euler[T++] = v;
distance = min(distance, dist_shop[to] + w);
}
if(is_shop[v]){
dist_shop[v] = 0;
}else{
dist_shop[v] = distance;
}
tout[v] = timer;
}
int is_parent(int par, int v){
return (tin[par] <= tin[v] && tout[v] <= tout[par]);
}
pair<int, int> sparse[LOG+3][N * 2+10];
int query_rmq(int a, int b) {
if(a > b) swap(a, b);
int f = lg[b-a + 1];
if(a == b) return sparse[f][a].ff;
return min(sparse[f][a].ff,sparse[f][(b - (1<<f)) < 0 ? 0 : (b - (1<<f))].ff);
}
int min_on_way(int u, int v) {
if(is_parent(u, v)) swap(u, v);
return query_rmq(range[u], lst[v]);
}
int can_reach(int v, int u, int closed){
if(is_parent(closed, v) or is_parent(closed, u)) return 0;
return 1;
}
/*int distance(int v, int u){
int LCA = lca(v, u);
return depth_sum[v] + depth_sum[u] - 2*depth_sum[LCA];
}*/
int close(int idx){
return (depth[edges[idx].ff] < depth[edges[idx].ss] ? edges[idx].ss : edges[idx].ff);
}
main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> s >> q >> e;
edges.push_back({-1, -1});
for(int i = 1;i < n; i++){
int a, b, w; cin >> a >> b >> w;
g[a].push_back({b, w});
g[b].push_back({a, w});
edges.push_back({a, b});
}
for(int i = 0;i < s; i++){
int x; cin >> x;
shops.push_back(x);
is_shop[x] = 1;
}
dfs(e, e);
// cout << "Euler path = ";
for(int i = 0;i < T; i++){
// cout << euler[i] << ' ';
sparse[0][i] = {dist_shop[euler[i]] - depth_sum[euler[i]], euler[i]};
}
// cout << '\n';
int logT = 0;
while ((1<<logT) < T) logT++;
for(int f = 0; f < logT; f++){
for(int i = 0;i + (1<<f) < T; i++){
sparse[f+1][i] = min(sparse[f][i], sparse[f][i + (1<<f)]);
}
}
lg[0] = 0;
for(int i = 2;i < T; i++){
lg[i] = lg[i / 2] + 1;
}
for(int i = 1;i <= n; i++){
// - depth_sum[euler[i].ss]
// cout << i << " = " << dist_shop[i] - depth_sum[euler[i]] << '\n';
}
// cout << '\n';
while(q--){
int idx, v; cin >> idx >> v;
if(can_reach(v, e, close(idx))){
cout << "escaped";
}else if(s == n){
cout << 0;
}else{
int mn = min_on_way(v, close(idx));
// cout << range[v] << " " << lst[close(idx)] << " = " << mn << '\n';
// cout << v << " " << close(idx) << " == " << mn << '\n';
mn+= depth_sum[v];
mn = min(mn, dist_shop[v]);
if(mn >= (int)1e15) cout << "oo";
else cout << mn;
}
cout << '\n';
}
return 0;
}
