///huynhocute123///
#include<bits/stdc++.h>
using namespace std;
#define S second
#define F first
#define pii pair<long long,long long>
#define piii pair<int,pair<int,int>>
#define pb push_back
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = b; i >= a; --i)
#define ALL(v) v.begin(),v.end()
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
//random_device rd;
//mt19937 rng(rd());
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
//#define int long long
const int maxN = 2 * 1e5 + 9;
const int modd = 1e9 + 7;
const int base = 2309;
const int MAX = 1e9+9;
const double pi = 3.14159265358979323846;
const double rad = 3.14159265358979323846 /180;
void minimize(long long &u, long long v){
if(v < u) u = v;
}
void maximize(int &u, int v){
if(v > u) u = v;
}
int n, k, t, m, res, q, a[maxN], root, shop[maxN], dep[maxN], in[maxN], out[maxN], cnt, Numshop;
long long dis[maxN], f[maxN];
int l, r;
pii edge[maxN], T[maxN][21];
bool isshop[maxN];
vector<pii> e[maxN];
void dfs(int u, int p){
in[u] =++cnt;
if(isshop[u]){
shop[u]=1;
f[u] = dis[u];
}
for(auto [x, w] : e[u]){
if(x == p)continue;
T[x][0].F = u;
dis[x] =dis[u] + w;
dep[x] =dep[u] +1;
dfs(x, u);
minimize(f[u], f[x]);
shop[u] +=shop[x];
}
out[u]= cnt;
}
bool ischild(int u ,int v){
/// u is partent v
return ( in[u] <= in[v] && out[u] >= out[v]);
}
void build(){
for(int i =1; i <= n ;i++)T[i][0].S =f[i];
for(int i= 1;i <= 20; i++){
for(int u= 1;u <= n ;u++){
T[u][i].F = T[T[u][i-1].F][i-1].F;
T[u][i].S = min(T[u][i-1].S , T[T[u][i-1].F][i-1].S);
}
}
}
long long jump(int u ,int v){
long long ans = MAX;
for(int i = 20 ;i >= 0 ;i--){
if(dep[u] - dep[v] + 1 >= ( 1 << i)){
minimize(ans, T[u][i].S);
u = T[u][i].F;
}
}
return ans;
}
void solve(){
cin >> n >> Numshop >> q >> root;
for(int i =1;i < n ; i++){
int x;cin >> l >> r >> x;
e[l].pb({r, x});
e[r].pb({l ,x});
edge[i]= {l ,r};
}
for(int i =1;i <= n ;i++)f[i]= MAX;
for(int i=1;i <= Numshop;i++){
int x;cin >> x;
isshop[x]= 1;
}
dfs(root ,0);
// for(int i =1;i <= n ;i++)cout << f[i] << " ";
for(int i =1;i <= n ;i++)f[i]-= 2 * dis[i];
build();
for(int ix =1; ix <= q; ix++){
int id , x;
cin >> id >> x;
int u = edge[id].F , v= edge[id].S;
int nod = (dep[u] > dep[v] ? u : v);
if(ischild(nod, x)){
if(shop[nod] == 0) cout << "oo" << '\n';
else cout << dis[x] + jump(x, nod) << '\n';
}else{
cout << "escaped" << '\n';
}
}
}
signed main(){
// freopen("name.inp","r",stdin);
// freopen("name.out","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(0);
inp("task.inp");
t = 1;
// cin >> t;
while( t-- )solve();
}
