#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()
int main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
ll n,s,q,e;
cin>>n>>s>>q>>e;
ll u[n],v[n],w[n];
vector<pair<ll,ll>>adj[n+1];
for(ll i=1;i<n;i++){
cin>>u[i]>>v[i]>>w[i];
adj[u[i]].pb({v[i],w[i]});
adj[v[i]].pb({u[i],w[i]});
}
bool shop[n+1];
fill(shop,shop+n+1,0);
for(ll i=1;i<=s;i++){
ll c;
cin>>c;
shop[c]=true;
}
ll cur=0;
ll ord[n+1][2],cnt[n+1],par[n+1];
par[e]=0;
function <void(ll,ll)> dfs=[&](ll x,ll p){
cnt[x]=(shop[x]);
ord[x][0]=++cur;
for(auto [y,w]:adj[x]){
if(y!=p){
par[y]=x;
dfs(y,x);
cnt[x]+=cnt[y];
}
}
ord[x][1]=++cur;
};
function <bool(ll,ll)> check=[&](ll i,ll j){
if(ord[i][0]<=ord[j][0]&&ord[j][1]<=ord[i][1]){
return false;
}
return true;
};
dfs(e,0);
while(q--){
ll i,r;
cin>>i>>r;
ll low=u[i];
if(par[v[i]]==u[i]){
low=v[i];
}
if(check(low,r)){
cout<<"escaped\n";
continue;
}
if(cnt[low]==0){
cout<<"oo\n";
continue;
}
cout<<0<<"\n";
}
}
