#include<bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define endl "\n"
#define pii pair<int,int>
using namespace std;
typedef long long ll;
const int N = 1e5 + 15;
const int lg = 17;
const ll INF = 1e18;
int n, s, q, root;
pii edges[N];
vector<pii> g[N];
int par[N][lg+1];
int h[N];
ll dist[N];
int tin[N], tout[N], timerDFS;
bool shop[N];
void dfs(int u, int p){
tin[u] = ++timerDFS;
for(auto [v, w] : g[u]) if(v != p){
h[v] = h[u] + 1;
dist[v] = dist[u] + w;
par[v][0] = u;
for(int j = 1; j <= lg; j++) par[v][j] = par[par[v][j-1]][j-1];
dfs(v,u);
}
tout[u] = timerDFS;
}
bool inside(int u, int v){
return tin[u] <= tin[v] && tout[v] <= tout[u];
}
ll best[N];
ll Up[N][lg+1];
void calc(int u, int p){
best[u] = INF; // there is no shop in subtree u
if(shop[u]) best[u] = dist[u];
for(auto [v, w] : g[u]) if(v != p){
calc(v,u);
best[u] = min(best[u], best[v]);
}
}
ll query(int v, int u){
ll ans = INF;
for(int j = lg; j >= 0; j--){
if(h[u] - h[v] >= (1 << j)){
ans = min(ans, Up[u][j]);
u = par[u][j];
}
}
return ans;
}
void solve(){
cin >> n >> s >> q >> root;
for(int i = 1; i < n; i++){
int u, v, w; cin >> u >> v >> w;
g[u].push_back(pii(v,w));
g[v].push_back(pii(u,w));
edges[i] = pii(u,v);
}
dfs(root,-1);
for(int i = 1; i < n; i++){
if(h[edges[i].first] > h[edges[i].second]) swap(edges[i].first, edges[i].second);
}
for(int i = 1; i <= s; i++){
int u; cin >> u;
shop[u] = true;
}
// dist[u] + dist[v] - 2*dist[lca]
// best[u] = dist[v] - 2*dist[lca] : v has shop, inside(u,v)
calc(root,-1);
for(int i = 1; i <= n; i++){
Up[i][0] = best[i] - 2*dist[i];
}
for(int j = 1; j <= lg; j++){
for(int i = 1; i <= n; i++){
Up[i][j] = min(Up[i][j-1], Up[par[i][j-1]][j-1]);
}
}
while(q--){
int id, node; cin >> id >> node;
int u, v; tie(u,v) = edges[id];
if(!inside(v,node)){
cout << "escaped" << endl;
continue;
}
if(best[v] == INF){// no shop in subtree v -> no shop for node
cout << "oo" << endl;
continue;
}
cout << dist[node] + query(edges[id].first, node) << endl;
}
}
signed main(){
ios_base::sync_with_stdio(NULL);
cin.tie(0); cout.tie(0);
#define task "task"
if(fopen(task".INP", "r")){
freopen(task".INP", "r", stdin);
freopen(task".OUT", "w", stdout);
}
int t; t = 1; //cin >> t;
while(t--) solve();
}
