#include <bits/stdc++.h>
using namespace std;
int const MAX=1e5+5;
int const LOG=20;
long long const INF=1e18;
int n,nrs,q,root;
struct edge{
int nod,len;
};
struct muchie{
int a,b;
}much[MAX];
vector<edge>tree[MAX];
int ancestor[MAX][LOG];
long long dist_shop[MAX][LOG];
bool shop[MAX];
long long nearest_sub[MAX];
long long dist_rt[MAX];
int niv[MAX];
void read(){
cin>>n>>nrs>>q>>root;
int i;
for(i=1;i<n;++i){
int a,b,w;
cin>>a>>b>>w;
tree[a].push_back({b,w});
tree[b].push_back({a,w});
much[i]={a,b};
}
for(i=1;i<=nrs;++i){
int sh;
cin>>sh;
shop[sh]=1;
}
}
void minself(long long& x,long long val){
if(x>val)
x=val;
}
long long dfs(int nod){
if(shop[nod])
nearest_sub[nod]=0;
else
nearest_sub[nod]=INF;
for(auto edg : tree[nod]){
int fiu=edg.nod;
int w=edg.len;
if(fiu!=ancestor[nod][0]){
ancestor[fiu][0]=nod;
niv[fiu]=niv[nod]+1;
dist_rt[fiu]=dist_rt[nod]+w;
minself(nearest_sub[nod],w+dfs(fiu));
}
}
return nearest_sub[nod];
}
long long dist(int nod,int anc){
return dist_rt[nod]-dist_rt[anc];
}
void get_rmq(){
int i,j;
for(i=1;i<=n;++i){
int tata=ancestor[i][0];
dist_shop[i][0]=dist(i,tata)+nearest_sub[tata];
}
for(j=1;j<LOG;++j)
for(i=1;i<=n;++i){
int anc=ancestor[i][j-1];
dist_shop[i][j]=dist_shop[i][j-1];
if(anc)
minself(dist_shop[i][j],dist(i,anc)+dist_shop[anc][j-1]);
ancestor[i][j]=ancestor[anc][j-1];
}
}
struct to_anc{
int anc;
long long ans;
};
to_anc lift(int nod,int lev){
long long ans=INF;
long long dst=0;
int anc=nod;
int i;
for(i=0;i<LOG;++i)
if(lev&(1<<i)){
minself(ans,dst+dist_shop[anc][i]);
dst+=dist(anc,ancestor[anc][i]);
anc=ancestor[anc][i];
}
return {anc,ans};
}
void solve(int nod,int anc){
if(niv[nod]<niv[anc]){
cout<<"escaped\n";
return;
}
int ances;
long long ans;
to_anc rasp;
rasp=lift(nod,niv[nod]-niv[anc]);
ances=rasp.anc;
ans=rasp.ans;
if(ances!=anc){
cout<<"escaped\n";
return;
}
minself(ans,nearest_sub[nod]);
if(ans==INF){
cout<<"oo\n";
return;
}
cout<<ans<<'\n';
}
void process_queries(){
int i;
for(i=1;i<=q;++i){
int id_e,nod;
cin>>id_e>>nod;
int anc;
int a,b;
a=much[id_e].a;
b=much[id_e].b;
if(a==ancestor[b][0])
anc=b;
else
anc=a;
solve(nod,anc);
}
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
read();
dfs(root);
get_rmq();
process_queries();
return 0;
}
