//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using Tree =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define rep(i, a, b) for (int i = a; i <= b; ++i)
#define per(i, b, a) for (int i = b; i >= a; --i)
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(), (v).end()
#define lsb(x) (x)&(-x)
void setIO(string name = "") {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);cout.tie(nullptr);
if (!name.empty()) {
freopen((name + ".in").c_str(), "r", stdin);
freopen((name + ".out").c_str(), "w", stdout);
}
}
ll fexp(ll a, ll b, ll m) {
if (b == 0) return 1LL;
ll p = a;
ll ans = 1;
while (b > 0) {
if (b % 2 != 0) ans = (ans*p)%m;
p = (p*p)%m;
b >>= 1;
}
return ans;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MAXN = 1e5+10;
const int INF = 1e18+5;
const int MOD = 1e9+7;
vector<pii> g[MAXN];
int mk[MAXN], sz[MAXN], dp[MAXN], dep[MAXN], ti[MAXN], to[MAXN], n;
int p[MAXN], id[MAXN], tp[MAXN], st[4*MAXN];
void update(int idx, int val) {
st[idx+=n] = val;
for (idx /= 2; idx; idx /= 2) st[idx] = min(st[2*idx], st[2*idx+1]);
}
int query(int lo, int hi) {
int ra = INF, rb = INF;
for (lo += n, hi += n + 1; lo < hi; lo /= 2, hi /= 2) {
if (lo & 1) ra = min(ra, st[lo++]);
if (hi & 1) rb = min(rb, st[--hi]);
}
return min(ra, rb);
}
int tii = 0;
int dfs_sz(int u, int par) {
sz[u] = 1;
dp[u] = (mk[u]?dep[u]:INF);
p[u] = par;
ti[u] = ++tii;
for (auto [v,w] : g[u]) {
if (v == par) continue;
dep[v] = dep[u] + w;
p[v] = u;
sz[u] += dfs_sz(v, u);
dp[u] = min(dp[u], dp[v]);
}
to[u] = ++tii;
return sz[u];
}
int ct = 1;
void dfs_hld(int cur, int par, int top) {
id[cur] = ct++;
tp[cur] = top;
update(id[cur], dp[cur]);
int h_chi = -1, h_sz = -1;
for (auto &[chi,w] : g[cur]) {
if (chi == par) continue;
if (sz[chi] > h_sz) {
h_sz = sz[chi];
h_chi = chi;
}
}
if (h_chi == -1) return;
dfs_hld(h_chi, cur, top);
for (auto &[chi,w] : g[cur]) {
if (chi == par || chi == h_chi) continue;
dfs_hld(chi, cur, chi);
}
}
int path(int x, int y) {
int ret = INF;
while (tp[x] != tp[y]) {
if (dep[tp[x]] < dep[tp[y]]) swap(x,y);
ret = min(ret,query(id[tp[x]],id[x]));
x = p[tp[x]];
}
if (dep[x] > dep[y]) swap(x,y);
ret = min(ret, query(id[x],id[y]));
return ret;
}
void solve() {
int s,q,e;cin >> n >> s >> q >> e;
vector<array<int,2>> edg;
rep(i,1,n-1) {
int u,v,w;cin >> u >> v >> w;
g[u].pb({v,w});
g[v].pb({u,w});
edg.pb({u,v});
}
rep(i,1,s) {
int u;cin >> u;
mk[u] = 1;
}
dfs_sz(e,-1);
rep(i,1,n) if (dp[i] != INF) dp[i] -= 2*dep[i];
dfs_hld(e,-1,e);
while (q--) {
int id, u;cin >> id >> u;
int cur = edg[id-1][0];
if (dep[edg[id-1][1]] > dep[cur]) cur = edg[id-1][1];
if (ti[u] < ti[cur] || to[u] > to[cur]) {
cout << "escaped\n";
continue;
}
int ans =path(u,cur);
if (ans == INF) cout << "oo\n";
else cout << ans + dep[u] << '\n';
}
}
int32_t main() {
setIO();
int tt = 1;
//cin >> tt;
while (tt-- > 0) solve();
}
