#include<bits/stdc++.h>
using namespace std;
#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 pb push_back
#define F first
#define S second
#define pii pair<int ,int>
bool minimize(int& a, int b){
if(a > b){
a = b;
return 1;
}
return 0;
}
bool minimizell(long long& a, long long b){
if(a > b){
a = b;
return 1;
}
return 0;
}
bool maximize(int& a, int b){
if(a < b){
a = b;
return 1;
}
return 0;
}
bool maximizell(long long& a, long long b){
if(a < b){
a = b;
return 1;
}
return 0;
}
const int maxN = 1e5 + 999;
vector<pii> e[maxN];
int n , q, numHouse, escape;
int cost[maxN];
int house[maxN];
pii Edge[maxN];
const long long MAXLL = 1e18 +9;
namespace sub1{
bool check(){
return (n <= 1000);
}
long long d[maxN];
bool vis[maxN];
void dfs(int u, int collapse){
vis[u] = 1;
for(auto X : e[u]){
int x = X.F , id = X.S;
if(vis[x] || id == collapse)continue;
d[x] = d[u] + cost[id];
dfs(x, collapse);
}
}
void solve(){
FOR(xcxc, 1, q){
int collapse ,root;
cin >> collapse >> root;
FOR(i, 1, n)vis[i] = 0;
d[root] = 0;
dfs(root, collapse);
if(vis[escape]){
cout << "escaped" << '\n';
continue;
}
long long mndis = MAXLL;
FOR(u , 1 ,numHouse){
if(vis[house[u]])minimizell(mndis , d[house[u]]);
}
if(mndis == MAXLL)cout << "oo" << '\n';
else cout << mndis << '\n';
}
}
}
namespace ac{
int dep[maxN];
long long dp[maxN] , f[maxN];
long long mx[maxN][20];
int in[maxN] , out[maxN], TICK;
int T[maxN][20];
void pre(int u ,int p){
in[u] = out[u] = ++TICK;
for(auto X : e[u]){
int x = X.F ,id = X.S;
if(x == p)continue;
dep[x] = dep[u] + 1;
T[x][0] = u;
f[x] = f[u] + cost[id];
pre(x, u);
minimizell(dp[u] , dp[x] + cost[id]);
}
out[u] = TICK;
}
bool isP(int p ,int u){
return (in[p] <= in[u] && out[u] <= out[p]);
}
long long jump(int u ,int p){
long long ans = MAXLL;
REP(i, 0 , 18){
if(dep[u] - dep[p] >= (1 << i)){
// cout << i << " "<<u << " " << T[u][i] << " " << mx[u][i] << '\n';
minimizell(ans, mx[u][i]);
u = T[u][i];
}
}
minimizell(ans, dp[u] - f[u]);
// cout << u << '\n';
return ans;
}
void solve(){
FOR(u, 1, n)dp[u] = MAXLL;
FOR(i ,1 ,numHouse)dp[house[i]] = 0;
pre(escape ,0);
FOR(u, 1, n){
mx[u][0] = dp[u] - f[u];
}
FOR(i, 1 , 18){
FOR(u, 1, n){
T[u][i] = T[T[u][i - 1]][i - 1];
mx[u][i] = min(mx[u][i - 1] , mx[T[u][i - 1]][i - 1]);
}
}
FOR(xcxc, 1, q){
int collapse ,x;
cin >> collapse >> x;
int u = Edge[collapse].F , v = Edge[collapse].S;
if(dep[u] < dep[v])swap(u ,v);
/// dep[u] <= dep[v]
if(isP(u ,x)){
long long ans = MAXLL;
minimizell(ans, dp[x]);
long long k = jump(x , u);
minimizell(ans ,k + f[x]);
// cout << dp[3] - f[3] + f[5];
if(ans > 1e17)cout << "oo" << '\n';
else cout << ans << '\n';
}else{
cout << "escaped" << '\n';
}
}
}
}
void solve(){
cin >> n >> numHouse >> q >> escape;
FOR(i, 1 , n - 1){
int u , v ;
cin >> u >> v >> cost[i];
e[u].pb({v, i});
e[v].pb({u ,i});
Edge[i] = {u , v};
}
FOR(i, 1, numHouse)cin >> house[i];
if(sub1::check())return sub1::solve();
ac::solve();
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
solve();
}
