#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
vector<pll> graph[100003];
pll edges[100003];
ll pre_order[100003];
ll post_order[100003];
ll iter=0;
ll dep[100003];
vector<pll> query[100003];
ll ans[100003];
bool shop[100003];
ll down[100003];
ll oo=1e18;
void dfs1(ll v, ll p){
pre_order[v]=iter++;
down[v]=oo;
dep[v]=dep[p]+1;
if (shop[v])down[v]=0;
for (auto [u,c] : graph[v]){
if (u==p)continue;
dfs1(u,v);
down[v]=min(down[v],c+down[u]);
}
post_order[v]=iter++;
}
bool fat(ll v, ll u){
return (pre_order[v]<=pre_order[u] && post_order[v]>=post_order[u]);
}
vector<pll> path;
ll sm=0;
void solve(ll v, ll par){
for (auto [ind,i] : query[v]){
ll u=edges[ind].second;
if (!fat(u,v)){
ans[i]=-1;
continue;
}
if (path.empty() || path.back().first<dep[u]){
ans[i]=oo;
continue;
}
ll l=0,p=path.size()-1,md;
while(l<p){
md=(l+p)/2;
if (path[md].first>=dep[u])p=md;
else l=md+1;
}
ans[i]=path[l].second+sm;
}
stack<pll> st;
for (auto [u,c] : graph[v]){
if (u==par)continue;
sm+=c;
while(path.size() && (path.back().second+sm>=down[u])){
st.push(path.back());
path.pop_back();
}
if (down[u]!=oo){
path.push_back({dep[u],down[u]-sm});
}
solve(u,v);
if (down[u]!=oo){
path.pop_back();
}
sm-=c;
for(;st.size();st.pop())path.push_back(st.top());
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
ll n,s,q,e;
cin >> n >> s >> q >> e;
for (ll i = 1,v,u,d; i<n; i++){
cin >> v >> u >> d;
edges[i]={v,u};
graph[v].push_back({u,d});
graph[u].push_back({v,d});
}
for (ll i = 1,v; i<=s; i++){
cin >> v;
shop[v]=true;
}
dfs1(e,0);
for (ll i = 1; i<n; i++)if (fat(edges[i].second,edges[i].first))swap(edges[i].first,edges[i].second);
for (ll i = 1,ind,v; i<=q; i++){
cin >> ind >> v;
query[v].push_back({ind,i});
}
solve(e,-1);
for (ll i = 1; i<=q; i++){
if (ans[i]==-1)cout << "escaped\n";
else if (ans[i]==oo)cout << "oo\n";
else cout << ans[i] << '\n';
}
}
