#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pb push_back
using namespace std;
const ll N=1e5+5;
const ll INF=1e18;
vector<pair<ll,ll>> g[N];
vector<pair<ll,ll>> roads;
ll tin[N], tout[N];
ll S[N];
ll ns,e,top,t=0;
void dfs(ll v, ll p){
tin[v]=t;
t++;
for(auto u : g[v]){
if(u.fi==p) continue;
dfs(u.fi,v);
}
tout[v]=t;
t++;
}
ll virs(int a, int b){
if(tin[a]<tin[b] && tout[a]>tout[b]) return 1;
return 0;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
ll n,s,q;
cin>>n>>s>>q>>top;
for(ll i=0; i<n-1; i++){
ll a,b,w;
cin>>a>>b>>w;
g[a].pb({b,w});
g[b].pb({a,w});
roads.pb({a,b});
}
for(ll i=0; i<s; i++){
ll a; cin>>a;
S[a]=1;
}
dfs(top,top);
for(ll i=0; i<q; i++){
ll ban,r;
cin>>ban>>r;
ll a=roads[ban-1].fi,b=roads[ban-1].se;
if(virs(b,a)) swap(b,a);
if(tin[a]<tin[r] && tout[a]>tout[r] && tout[b]>=tout[r] && tin[b]<=tin[r]) cout<<"oo\n";
else cout<<"escaped\n";
}
return 0;
}
