/****ThanhCodeDao*****/
/*******Azazel*******/
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define pb push_back
#define checkbit(mask,i) ((mask>>i)&1)
#define bit(i) (1<<i)
#define MLog 18
typedef long long ll;
const ll maxN = 1e5+5, modd = 1e9+7;
vector<pair<ll,ll>> adj[maxN];
int n,s,q,e;
int c[maxN];
int st[maxN],fn[maxN],cnt = 0;
ll d[maxN];
int pa[MLog+1][maxN],h[maxN];
pair<int,int> E[maxN];
void pre_dfs(int u,int par){
st[u] = ++cnt;
h[u] = h[par] + 1;
pa[0][u] = par;
for(pair<ll,ll> pp : adj[u]){
ll v = pp.F, w = pp.S;
if(v==par) continue;
d[v] = d[u] + w;
pre_dfs(v,u);
}
fn[u] = cnt;
}
void build_lca(){
for(int i = 1;i<=MLog;i++){
for(int j = 1;j<=n;j++){
pa[i][j] = pa[i-1][pa[i-1][j]];
}
}
}
int getlca(int u,int v){
if(h[u] > h[v]) swap(u,v);
for(int i = MLog;i>=0;i--){
if(h[u] <= h[pa[i][v]]){
v = pa[i][v];
}
}
if(u==v) return u;
for(int i = MLog;i>=0;i--){
if(pa[i][u] != pa[i][v]){
u = pa[i][u];
v = pa[i][v];
}
}
return pa[0][u];
}
void sub12(){
for(int test = 1;test<=q;test++){
int i,r;
cin >> i >> r;
int u = E[i].F, v = E[i].S;
if(h[u] > h[v]) swap(u,v);
if(st[v] <= st[r] && fn[r] <= fn[v]){
ll ans = 1e17;
for(int j = 1;j<=s;j++){
if(st[v] <= st[c[j]] && fn[c[j]] <= fn[v]){
ans = min(ans,d[r] + d[c[j]] - 2*d[getlca(r,c[j])]);
}
}
if(ans == 1e17){
cout << "oo" << '\n';
}else{
cout << ans << '\n';
}
}else{
cout << "escaped" << '\n';
}
}
}
void sub3(){
for(int test = 1;test<=q;test++){
int i,r;
cin >> i >> r;
int u = E[i].F, v = E[i].S;
if(h[u] > h[v]) swap(u,v);
if(st[v] <= st[r] && fn[r] <= fn[v]){
cout << 0 << '\n';
}else{
cout << "escaped" << '\n';
}
}
}
void solve() {
cin >> n >> s >> q >> e;
for(int i = 1; i<=n-1; i++) {
int u,v,w;
cin >> u >> v >> w;
adj[u].pb({v,w});
adj[v].pb({u,w});
E[i].F = u;
E[i].S = v;
}
for(int i = 1; i<=s; i++) {
cin >> c[i];
}
pre_dfs(e,0);
build_lca();
if(q*s<=5e7) {
sub12();
return;
}
if(s==n) {
sub3();
return;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
//freopen("inp.txt","r",stdin);
//freopen("out.txt","w",stdout);
solve();
return 0;
}
