#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define int ll
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vll;
const ll maxn = 1e5 + 5;
const ll inf = LLONG_MAX/2;
int N, S, Q, E;
ii road[maxn];
vii adj[maxn];
set<int> shop;
vi tin(maxn);
vi tout(maxn);
vll dist(maxn, inf);
int par[maxn][20];
ll par_w[maxn][20];
ll par_s[maxn][20];
int cnt = 0;
void dfs(int u) {
tin[u] = cnt; cnt++;
for(auto [v, w] : adj[u]) if(v != par[u][0]) {
par[v][0] = u;
par_w[v][0] = w;
dfs(v);
dist[u] = min(dist[u], dist[v] + w);
}
if(shop.count(u)) dist[u] = 0;
tout[u] = cnt; cnt++;
}
bool is_anc(int v, int anc) {
return tin[v] >= tin[anc] && tout[v] <= tout[anc];
}
void lifting() {
for(int j = 1; j <= N; j++) {
par_s[j][0] = min(par_w[j][0] + dist[par[j][0]], dist[j]);
}
for(int i = 1; i <= 19; i++) for(int j = 1; j <= N; j++) {
par[j][i] = par[par[j][i-1]][i-1];
par_w[j][i] = par_w[par[j][i-1]][i-1] + par_w[j][i-1];
par_s[j][i] = par_w[j][i] + dist[par[j][i]];
par_s[j][i] = min(min(par_s[j][i], par_s[j][i-1]), par_s[par[j][i-1]][i-1] + par_w[j][i-1]);
}
}
int32_t main() {
cin >> N >> S >> Q >> E;
int u, v, w;
for(int i = 1; i < N; i++) {
cin >> u >> v >> w;
road[i] = {u, v};
adj[u].pb({v, w});
adj[v].pb({u, w});
}
for(int i = 0; i < S; i++) {
cin >> v; shop.insert(v);
}
par[E][0] = 0;
par_w[E][0] = 0;
dfs(E);
lifting();
int I, R, top;
ll res;
while(Q--) {
cin >> R >> I;
auto [u, v] = road[R];
if(is_anc(I, u) && is_anc(I, v)) {
top = (is_anc(u, v) ? u : v);
int x = I;
ll wt = 0;
res = inf;
/*for(int i = 19; i >= 0; i--) if(is_anc(par[x][i], top)) {
res = min(res, par_s[x][i] + wt);
x = par[x][i];
wt += par_w[x][i];
}*/
res = dist[x];
while(x != top) {
wt += par_w[x][0];
x = par[x][0];
res = min(res, dist[x] + wt);
}
if(res < inf) cout << res << endl;
else cout << "oo" << endl;
} else {
cout << "escaped" << endl;
}
}
return 0;
}
