#include <bits/stdc++.h>
#define suiii ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ll long long
#define co cout<<
//#pragma GCC optimize("O3,Ofast,unroll-loops")
//#pragma GCC target("avx2,sse3,sse4,avx")
using namespace std;
//stuff
int n,s,q,e;
const int maxn=1e5+5,N=exp2(ceil(log2(maxn)));
vector<array<int,3>>v[maxn];
vector<int>shops;
int tre[N*4];
int num=1;
pair<int,int>node[maxn]={};
pair<int,int>par[maxn];
int depth[maxn];
vector<pair<int,int>>theroads;
pair<int,int>tab[maxn][20];
void dfs(int x){
node[x]={num,0};
depth[x]=depth[par[x].first]+1;
num++;
for(auto i:v[x]){
if(i[1]==par[x].first) continue;
par[i[1]]={node[x].first,i[2]};
dfs(i[1]);
}
node[x]={node[x].first,num};
}
void maketable(int x){
if(x==0){
for(int i=1;i<=n;i++){
tab[i][x]=par[i];
}
}
else{
for(int i=1;i<=n;i++){
tab[i][x].first=tab[tab[i][x-1].first][x-1].first;
tab[i][x].second=tab[i][x-1].second+tab[tab[i][x-1].first][x-1].second;
}
}
}
pair<int,int>lca(int a,int b){
int diff=abs(depth[a]-depth[b]);
int ans=0;
if(diff){
if(depth[a]<depth[b]){
int curr=b;
for(int i=19;i>=0;i--){
if(((1<<i)&diff)>0){
ans+=tab[curr][i].second;
curr=tab[curr][i].first;
}
}
b=curr;
}
else if(depth[a]>depth[b]){
int curr=a;
for(int i=19;i>=0;i--){
if(((1<<i)&diff)>0){
ans+=tab[curr][i].second;
curr=tab[curr][i].first;
}
}
a=curr;
}
}
if(a==b) return {a,ans};
for(int i=19;i>=0;i--){
if(tab[a][i].first!=tab[b][i].first&&tab[a][i].first!=0&&tab[b][i].first!=0){
ans+=tab[a][i].second;
a=tab[a][i].first;
ans+=tab[b][i].second;
b=tab[b][i].first;
}
}
return {par[a].first,ans+par[a].second};
}
void solve(){
cin>>n>>s>>q>>e;
theroads.push_back({-1,-1});
for(int i=1;i<n;i++){
int a,b,c;
cin>>a>>b>>c;
v[a].push_back({c,b,i});
v[b].push_back({c,a,i});
theroads.push_back({a,b});
}
par[1]={0,0};
dfs(1);
for(int i=0;i<s;i++){
int a;
cin>>a;
shops.push_back(node[a].first);
}
sort(shops.begin(),shops.end());
for(int i=0;i<=19;i++) maketable(i);
while(q--){
int del,idx;
cin>>del>>idx;
int copy=node[idx].first;
int copy1=node[e].first;
int a,b;
a=node[theroads[del].first].first;
b=node[theroads[del].second].first;
if(depth[a]<depth[b]) swap(a,b);
if((lca(a,copy).first==a&&lca(a,copy1).first==a)||(lca(a,copy).first!=a&&lca(a,copy1).first!=a)){
co "escaped\n";
}
else{
int dis=1e18;
if(lca(a,copy).first==a){
// auto it=lower_bound()
}
else{
if(copy!=n){
if(lca(a,copy+1).first!=a){
dis=min(dis,lca(copy,copy+1).second);
}
}
if(copy!=1){
if(lca(a,copy-1).first!=a){
dis=min(dis,lca(copy,copy-1).second);
}
}
}
co 0<<'\n';
}
}
}
int main()
{
suiii
int tt=1;
// cin>>tt;
while(tt--){
solve();
}
return 0;
}
