// Author: caption_mingle
#include "bits/stdc++.h"
using namespace std;
#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define ll long long
const int mod = 1e9 + 7;
const ll inf = 2e18;
const int N = 1e5 + 7;
int n, s, q, e;
pair<int, int> edge[N];
int in[N], out[N], timer;
bool mark[N];
ll ans[N], st[N * 4], lazy[N * 4], lev[N];
vector<pair<int, int>> g[N], ev[N];
void push(int i) {
if(lazy[i]) {
ll x = lazy[i];
lazy[i] = 0;
st[i * 2] += x;
st[i * 2 + 1] += x;
lazy[i * 2] += x;
lazy[i * 2 + 1] += x;
}
}
void update(int i, int l, int r, int u, int v, ll x) {
if(l > v or r < u) return;
if(u <= l and r <= v) {
st[i] += x;
lazy[i] += x;
return;
}
push(i);
int m = (l + r) >> 1;
update(i * 2, l, m, u, v, x);
update(i * 2 + 1, m + 1, r, u, v, x);
st[i] = min(st[i * 2], st[i * 2 + 1]);
}
ll get(int i, int l, int r, int u, int v) {
if(l > v or r < u) return inf;
if(u <= l and r <= v) return st[i];
push(i);
int m = (l + r) >> 1;
return min(get(i * 2, l, m, u, v), get(i * 2 + 1, m + 1, r, u, v));
}
void pre_dfs(int u, int p) {
in[u] = ++timer;
for(auto [v, w] : g[u]) {
if(v == p) continue;
lev[v] = lev[u] + w;
pre_dfs(v, u);
}
out[u] = timer;
}
bool inside(int u, int v) {
return in[u] <= in[v] and out[v] <= out[u];
}
void dfs(int u, int p) {
for(auto [eid, id] : ev[u]) {
auto [par, v] = edge[eid];
if(inside(v, u)) {
ans[id] = get(1, 1, n, in[v], out[v]);
} else {
ans[id] = min(get(1, 1, n, 1, in[v] - 1), get(1, 1, n, out[v] + 1, n));
}
}
for(auto [v, w] : g[u]) {
if(v == p) continue;
update(1, 1, n, in[v], out[v], -w);
update(1, 1, n, 1, in[v] - 1, w);
update(1, 1, n, out[v] + 1, n, w);
dfs(v, u);
update(1, 1, n, in[v], out[v], w);
update(1, 1, n, 1, in[v] - 1, -w);
update(1, 1, n, out[v] + 1, n, -w);
}
}
signed main() {
cin.tie(0) -> sync_with_stdio(0);
#define task ""
if(fopen(task ".INP", "r")) {
freopen(task ".INP", "r", stdin);
freopen(task ".OUT", "w", stdout);
}
cin >> n >> s >> q >> e;
for(int i = 1; i < n; i++) {
int u, v, w; cin >> u >> v >> w;
g[u].pb({v, w});
g[v].pb({u, w});
edge[i] = {u, v};
}
pre_dfs(1, 0);
for(int i = 1; i < n; i++) {
auto& [u, v] = edge[i];
if(in[u] > in[v]) swap(u, v);
}
for(int i = 1; i <= s; i++) {
int x; cin >> x;
mark[x] = 1;
}
for(int i = 1; i <= q; i++) {
int id, x; cin >> id >> x;
auto [u, v] = edge[id];
if(inside(v, e) and inside(v, x)) {
ans[i] = -1;
} else if(!inside(v, e) and !inside(v, x)) {
ans[i] = -1;
} else {
ev[x].pb({id, i});
}
}
for(int i = 1; i <= n; i++) {
ll val = inf;
if(mark[i]) val = lev[i];
update(1, 1, n, in[i], in[i], val);
}
dfs(1, 0);
for(int i = 1; i <= q; i++) {
if(ans[i] == -1) cout << "escaped";
else if(ans[i] > 1e15) cout << "oo";
else cout << ans[i];
cout << ln;
}
cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}
