#include<bits/stdc++.h>
#define int long long
#define f first
#define s second
#define repeat(i,a,b) for(int i=a;i<=b;i++)
#define pb push_back
#define p push
#define pii pair<int,int>
#define piii pair<int,pair<int,int>>
#define vii vector<vector<int>>
#define vi vector<int>
//#define DEBUG
//#define multipletest
using namespace std;
const int LIM=1e5;
const int mod=1e9+7;
const int maxn=20;
const int inf=1e18;
int n,m,x,y,k,t,e,q,s;
int dx[8]={1,-1,0,0,-1,-1,1,1};
int dy[8]={0,0,-1,1,1,-1,1,-1};
char c;
int a[LIM+5],factorial[(1<<maxn)+5],inv_fact[(1<<maxn)+5];
bool notprime[LIM+5];
vector<pii> adj[LIM+5];
map<int,int> mp;
char grid[100+5][100+5];
int power(int a,int b){
if(b==0) return 1;
int t=power(a,b/2);
t = t * t %mod;
if(b%2==1) t = t * a %mod;
return t;
}
bool check(int x,int y){
if(x<=0 || x>n || y<=0 || y>m || grid[x][y]=='T'){
return false;
}
return true;
}
class DSU{
int *parent;
int *rank;
int *tot;
public:
DSU(int n){
rank=new int[n+5];
parent=new int[n+5];
tot=new int [n+5];
for(int i=0;i<n+5;i++){
parent[i]=i;
rank[i]=0;
tot[i]=1;
}
}
int find(int i){
if(parent[i]==i){
return i;
}
return parent[i]=find(parent[i]);
}
void unite(int u,int v){
int i=find(u);
int j=find(v);
if(i!=j){
if(rank[i]>rank[j]){
parent[j]=i;
tot[i]+=tot[j];
}
else if(rank[i]<rank[j]){
parent[i]=j;
tot[j]+=tot[i];
}
else{
parent[j]=i;
rank[i]++;
tot[i]+=tot[j];
}
}
}
int total(int u){
return tot[u];
}
};
void precal(int n){
factorial[0]=1;
inv_fact[0]=1;
for (int i = 1; i <n; ++i)
{
factorial[i] = factorial[i - 1] * i % mod;
inv_fact[i] = inv_fact[i - 1] * power(i, mod - 2) % mod;
}
}
int choose(int n,int k){
if(k<0 || k>n) return 0;
return factorial[n] * inv_fact[n-k] % mod * inv_fact[k] %mod;
}
void Sieve(){
notprime[0]=notprime[1]=true;
for(int i=2;i<LIM+5;++i){
if(notprime[i]==false){
for(int j=i*i;j<LIM+5;j+=i){
notprime[j]=true;
}
}
}
}
bool shop[LIM+5];
int tail[LIM+5];
int depth[LIM+5],disc[LIM+5],dp[LIM+5],low[LIM+5];
int up[20][LIM+5];
int updist[20][LIM+5];
int upshop[20][LIM+5];
pii edges[LIM+5];
int timedfs=0;
void dfs(int u,int parent){
disc[u]=++timedfs;
up[0][u]=parent;
for(auto to:adj[u]){
if(to.f!=parent){
int v=to.f;
int w=to.s;
depth[v]=depth[u]+1;
dfs(v,u);
updist[0][v]=w;
dp[u]=min(dp[u],(dp[v]==inf?inf:dp[v]+w));
}
}
tail[u]=timedfs;
}
void solve(){
//Sieve();
// precal();
cin>>n>>s>>q>>e;
for(int i=1;i<=n-1;++i){
int u,v,w;
cin>>u>>v>>w;
adj[u].push_back({v,w});
adj[v].push_back({u,w});
edges[i].f=u,edges[i].s=v;
}
for(int i=1;i<=n;++i){
dp[i]=inf;
}
for(int i=0;i<s;++i){
int u;
cin>>u;
dp[u]=0;
}
dfs(e,e);
for(int i=0;i<20;++i){
upshop[i][e]=dp[e];
}
for(int i=1;i<=n;++i){
upshop[0][i]=dp[i];
}
// cout<<dp[e]<<endl;
for(int i=1;i<20;++i){
for(int j=1;j<=n;++j){
up[i][j]=up[i-1][up[i-1][j]];
updist[i][j]=updist[i-1][j] + updist[i-1][up[i-1][j]];
upshop[i][j]=min(upshop[i-1][j],updist[i-1][j] + upshop[i-1][up[i-1][j]] );
}
}
// for(int i=1;i<20;++i){
// for(int j=1;j<=n;++j){
// cout<<upshop[i][j] <<" ";
// }
// cout<<endl;
// }
while(q--){
int id,vertex;
cin>>id>>vertex;
int u=edges[id].f,v=edges[id].s;
// cout<<depth[u]<<" "<<depth[v]<<endl;
if(depth[u]>depth[v]){
swap(u,v);
}
if(disc[v]<=disc[vertex] && tail[v]>=tail[vertex]){
int ans=inf;
int jump= depth[vertex]-depth[u];
int temp=0,path=0;
while(jump>0){
if(jump%2==1){
ans = min(ans , (upshop[temp][vertex]==inf?inf : path + upshop[temp][vertex]));
path+=updist[temp][vertex];
vertex = up[temp][vertex];
}
jump>>=1;
temp++;
}
if(ans==inf) cout<<"oo"<<endl;
else cout<<ans<<endl;
}
else{
cout<<"escaped"<<endl;
}
}
}
signed main(){
// freopen(".inp","r",stdin);
// freopen(".out","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int test;
test=1;
#ifdef multipletest
cin>>test;
#endif
while(test--){
solve();
#ifdef DEBUG
cerr << "Runtime is: " << clock() * 1.0 / CLOCKS_PER_SEC << endl;
#endif
}
}
