#include <iostream>
#include <vector>
#include <set>
using namespace std;
const int N=1e5+10;
vector<pair<int,int>> ma[N],query[N];
int ans[N];
set<int> cur;
void dfs(int x,int p=-1)
{
for(auto [ind,bl]:query[x])
if(cur.find(bl)==cur.end())
ans[ind]=1;
for(auto [y,ind]:ma[x])
{
if(y!=p)
{
cur.insert(ind);
dfs(y,x);
cur.erase(ind);
}
}
}
int main()
{
int n,s,q,e;
cin>>n>>s>>q>>e;
// n is Number of villages
// s is number of villages with shops
// q is queries
// e is the exit village
for(int i=1;i<n;i++)
{
int a,b,w;
cin>>a>>b>>w;
ma[a].push_back({b,i});
// Edge between a and b with length w
ma[b].push_back({a,i});
}
int sp;
for(int i=0;i<s;i++)
cin>>sp;
for(int i=0;i<q;i++)
{
int r,l;
cin>>r>>l;
query[l].push_back({i,r});
}
dfs(e);
for(int j=0;j<q;j++)
{
cout<<((ans[j])?"escaped\n":"0\n");
}
return 0;
}//as
