/*
Author: Nguyen Chi Thanh - High School for the Gifted - VNU.HCM (i2528)
*/
#include <bits/stdc++.h>
using namespace std;
/* START OF TEMPALTE */
#define int long long
#define ll long long
#define ull unsigned long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define popcount __builtin_popcountll
#define all(x) (x).begin(), (x).end()
#define BIT(x, i) (((x) >> (i)) & 1)
#define MASK(x) (1ll << (x))
#define SZ(a) ((int32_t)a.size())
#define debug(a, l, r) {for (int _i = (l); _i <= (r); ++_i) cout << (a)[_i] << ' '; cout << '\n';}
template<class X, class Y>
bool minimize(X &x, const Y &y) {
if (x > y) {
x = y;
return true;
} else return false;
}
template<class X, class Y>
bool maximize(X &x, const Y &y) {
if (x < y) {
x = y;
return true;
} else return false;
}
/* END OF TEMPALTE */
const int MAXN = 1e5 + 5;
const int LG = 17;
const int INF = (int)1e18 + 5;
int n, s, q, e, tin[MAXN], tout[MAXN], depth[MAXN], dp[MAXN], val[MAXN], h[MAXN];
int up[LG + 1][MAXN], mi_jump[LG + 1][MAXN];
vector<pii> adj[MAXN];
pii edges[MAXN];
bool shop[MAXN];
void init() {
cin >> n >> s >> q >> e;
for (int i = 1; i < n; ++i) {
int u, v, w; cin >> u >> v >> w;
adj[u].push_back({v, w});
adj[v].push_back({u, w});
edges[i] = {u, v};
}
for (int i = 1; i <= s; ++i) {
int u; cin >> u;
shop[u] = 1;
}
for (int i = 1; i <= n; ++i) dp[i] = val[i] = INF;
int timer = 0;
function<void(int,int)> preDfs = [&] (int u, int par) {
tin[u] = ++timer;
up[0][u] = par;
if (shop[u]) dp[u] = 0;
for (auto &e : adj[u]) {
int v = e.fi, w = e.se;
if (v == par) continue;
depth[v] = depth[u] + w;
h[v] = h[u] + 1;
preDfs(v, u);
if (dp[v] != INF) minimize(dp[u], dp[v] + w);
}
tout[u] = timer;
};
preDfs(e, 0);
for (int i = 1; i <= n; ++i) {
if (dp[i] != INF)
val[i] = dp[i] - depth[i];
}
for (int i = 1; i <= n; ++i)
mi_jump[0][i] = val[i];
mi_jump[0][0] = INF;
for (int j = 1; j <= LG; ++j) {
up[j][0] = 0;
mi_jump[j][0] = INF;
for (int i = 1; i <= n; ++i) {
up[j][i] = up[j - 1][up[j - 1][i]];
mi_jump[j][i] = min(
mi_jump[j - 1][i],
mi_jump[j - 1][up[j - 1][i]]
);
}
}
}
void solve() {
for (int qr = 1; qr <= q; ++qr) {
int eid, start;
cin >> eid >> start;
int u = edges[eid].fi, v = edges[eid].se;
if (depth[u] > depth[v]) swap(u, v);
if (tin[v] <= tin[start] && tin[start] <= tout[v]) {
int minPath = INF;
int diff = h[start] - h[v] + 1;
int cur = start;
for (int j = LG; j >= 0; --j) {
if (BIT(diff, j)) {
minimize(minPath, mi_jump[j][cur]);
cur = up[j][cur];
}
}
if (minPath == INF) cout << "oo\n";
else cout << minPath + depth[start] << '\n';
} else cout << "escaped\n";
}
}
signed main() {
#ifdef NCTHANH
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ios_base::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
init();
solve();
return 0;
}
