#include <bits/stdc++.h>
#define MAXN 100001
using namespace std;
vector<int> adj_lst[MAXN];
int depth[MAXN];
int par[MAXN][20];
void dfs(int i){
for( int j : adj_lst[i] ){
if( depth[j] ) continue;
par[j][0] = i; depth[j] = depth[i]+1;
dfs(j);
}
}
vector<pair<int, int>> edgeList;
int jmp(int i, int diff){
for( int k{19} ; k >= 0 ; --k ) if( diff&(1<<k) ) i = par[i][k];
return i;
}
int main(){
int nodes, edges, shops, Q, E;
cin>>nodes>>shops>>Q>>E; edges = nodes-1;
while( edges-- ){
int u, v, w;
cin>>u>>v>>w;
adj_lst[u].push_back(v);
adj_lst[v].push_back(u);
edgeList.push_back({u, v});
}
depth[E] = 1;
dfs(E);
//for( int i{1} ; i <= nodes ; ++i ) cout<<depth[i]<<" "; cout<<'\n';
while( shops-- ){ int x; cin>>x; }
for( int k{1} ; k < 20 ; ++k ) for( int i{1} ; i <= nodes ; ++i ) par[i][k] = par[par[i][k-1]][k-1];
while( Q-- ){
int i, r;
cin>>i>>r;
auto x = edgeList[i-1];
int u = x.first, v = x.second;
if( depth[u] < depth[v] ) swap(u, v);
if( depth[r] < depth[u] ) cout<<"escaped\n";
else{
int diff = depth[r] - depth[u];
int rch = jmp(r, diff);
//cout<<diff<<" "<<rch<<'\n';
if( rch == u ) cout<<r<<'\n';
else cout<<"escaped\n";
}
}
return 0;
}
