#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define F first
#define S second
using namespace std;
const int N = 1e5 + 10;
const int mod = 1e9 + 7;
const long long inf = 1e18;
const int LOG = 17;
vector<pair<int,int>>g[N];
int dist[N],dp[N],up[N][LOG],mn[N][LOG],in[N],out[N],timer = 0;
bool shop[N],have[N];
pair<int,int>edges[N];
void dfs(int x,int par) {
in[x] = ++timer;
have[x] = shop[x];
for(auto X : g[x]) {
if(X.F == par) continue;
dist[X.F] = dist[x] + X.S;
dfs(X.F,x);
have[x] |= have[X.F];
}
out[x] = timer;
}
void Dfs(int x,int par) {
if(shop[x]) dp[x] = dist[x];
else dp[x] = inf;
for(auto X : g[x]) {
if(X.F == par) continue;
Dfs(X.F,x);
dp[x] = min(dp[x],dp[X.F]);
}
}
bool In(int u,int v) {
return in[u] <= in[v] && out[u] >= out[v];
}
int lift(int x,int v) {
int res = inf;
for(int j = LOG - 1; j >= 0; j--) {
if(In(v,up[x][j])) {
res = min(res,mn[x][j]);
x = up[x][j];
}
}
//cout << "dbg " << dp[x] << endl;
res = min(res,dp[x]);
return res;
}
void setup(int x,int par) {
up[x][0] = par;
mn[x][0] = dp[x];
for(int j = 1; j < LOG; j++) {
up[x][j] = up[up[x][j - 1]][j - 1];
mn[x][j] = min(mn[x][j - 1],mn[up[x][j - 1]][j - 1]);
}
for(auto X : g[x]) {
if(X.F == par) continue;
setup(X.F,x);
}
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n,s,q,e;
cin >> n >> s >> q >> e;
for(int i = 1; i <= n - 1; i++) {
int u,v,w;
cin >> u >> v >> w;
edges[i] = {u,v};
g[u].pb({v,w});
g[v].pb({u,w});
}
for(int i = 1; i <= s; i++) {
int x;
cin >> x;
shop[x] = true;
}
dfs(e,0);
Dfs(e,0);
for(int i = 1; i <= n; i++) dp[i] -= 2 * dist[i];
setup(e,0);
/*cout << dp[3] << endl;
cout << lift(5,3) + dist[5] << endl;*/
while(q--) {
int i,r;
cin >> i >> r;
int node = edges[i].F;
if(in[edges[i].F] < in[edges[i].S]) node = edges[i].S;
if(!In(node,r)) {
cout << "escaped\n";
continue;
}else if(!have[node]) {
cout << "oo\n";
continue;
}
cout << lift(r,node) + dist[r] << "\n";
}
return 0;
}
