#include <bits/stdc++.h>
/*
Chang ki si xuyen man dem
Di lac vao trong giac mong
*/
using namespace std;
using ll = long long;
#define int long long
#define pii pair<ll, ll>
#define fi first
#define se second
const ll N = 5e5 + 5, inf = 1e18, mod = 1e9 + 7, block = 320, lim = 19;
int n, q, s, E;
vector <pii> adj[N];
int c[N]; // exist shop or not
int in[N], out[N], tdfs;
int h[N], dp[N], dp1[N];
// dp[anc] is min of h[v] - 2 * h[anc] while dp1[anc] is min of h[v]
int st[N][lim + 1], W[N][lim + 1]; // W[i][0] = min(dp[i])
pii edge[N];
int dist[N];
void dfs(int u, int par) { // preprocess
in[u] = out[u] = ++tdfs;
if (c[u]) dp1[u] = dist[u];
else dp1[u] = inf;
for (auto [v, w] : adj[u]) {
if (v != par) {
h[v] = h[u] + 1;
dist[v] = dist[u] + w;
dfs(v, u);
dp1[u] = min(dp1[u], dp1[v]);
}
}
out[u] = tdfs;
if (dp1[u] != inf) dp[u] = dp1[u] - 2 * dist[u];
else dp[u] = inf;
}
void dfs1(int u, int par) { // build binary lifting
st[u][0] = par;
W[u][0] = dp[u];
for (int i = 1; i <= lim; i++) {
st[u][i] = st[st[u][i - 1]][i - 1];
W[u][i] = min(W[u][i - 1], W[st[u][i - 1]][i - 1]);
}
for (auto [v, w] : adj[u]) {
if (v != par) {
dfs1(v, u);
}
}
}
bool check(int u, int v) { // check if v in subtree u
return in[u] <= in[v] && out[v] <= out[u];
}
void solve() {
dfs(E, 0);
for (int i = 0; i <= lim; i++) {
st[0][i] = 0;
W[0][i] = inf;
}
dfs1(E, 0);
// cout << h[3] << ' ' << dp1[3] << W[5][0] << '\n';
for (int i = 1; i <= q; i++) {
int id, R;
cin >> id >> R;
int u = edge[id].fi, v = edge[id].se;
int low_edge = u;
if (in[u] < in[v]) low_edge = v; // the node lower than other node
// if (i == 2) cout << low_edge << ' ' << R << ' ' << check(low_edge, R) << '\n';
if (!check(low_edge, R)) { // R can connect with E
cout << "escaped" << '\n';
}
else { // R is in the subtree of low_edge
int t = R;
int val = inf;
// cout << "now: " << h[t] << ' ' << h[low_edge] << '\n';
for (int j = lim; j >= 0; j--) {
if (h[t] - (1 << j) < h[low_edge]) continue;
val = min(val, W[t][j]);
// cout << t << ' ';
t = st[t][j];
}
// cout << "at1: " << t << '\n';
val = min(val, dp[t]);
// cout << "at: " << val << '\n';
if (val == inf) cout << "oo" << '\n';
else cout << dist[R] + val << '\n';
}
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(0);
if (fopen(".inp", "r")) {
freopen(".inp", "r", stdin);
freopen(".out", "w", stdout);
}
cin >> n >> s >> q >> E;
for (int i = 1; i < n; i++) {
int u, v, w;
cin >> u >> v >> w;
edge[i] = make_pair(u, v);
adj[u].emplace_back(v, w);
adj[v].emplace_back(u, w);
}
for (int i = 1; i <= s; i++) {
int x;
cin >> x;
c[x] = 1;
}
solve();
return 0;
}
