// ¯\_(ツ)_/¯
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define all(x) (x).begin(),(x).end()
#define X first
#define Y second
#define sep ' '
#define endl '\n'
#define debug(x) cerr << #x << ": " << x << endl;
const ll MAXN = 1e6 + 10;
const ll INF = 1e18;
const ll MOD = 1e9 + 7; // 998244353; // 1e9 + 9;
const ll LOG = 20;
int n, s, q, e, H[MAXN], tin[MAXN], tout[MAXN], T, par[MAXN][LOG];
vector<pair<int, int>> adj[MAXN];
vector<pair<int, int>> edges;
bool B[MAXN], sub_g[MAXN];
ll dist[MAXN], dp_up[MAXN], Down[MAXN][LOG], Up[MAXN][LOG];
pair<pll, pll> dp[MAXN];
void dfs(int v, int p) {
par[v][0] = p;
tin[v] = T++;
H[v] = H[p] + 1;
dp[v] = {{INF, 0}, {INF, 0}};
if (v == e) sub_g[v] = true;
if (B[v]) dp[v].X = {0, v};
for (auto e : adj[v]) {
int u = e.X, w = e.Y;
if (u == p) continue;
dist[u] = dist[v] + w;
dfs(u, v);
sub_g[v] |= sub_g[u];
if (dp[u].X.X + w < dp[v].X.X) {
dp[v].Y = dp[v].X;
dp[v].X = {dp[u].X.X + w, u};
} else if (dp[u].X.X + w < dp[v].Y.X) dp[v].Y = {dp[u].X.X + w, u};
}
tout[v] = T++;
}
bool SubG(int v, int u) {
return tin[v] <= tin[u] && tout[v] >= tout[u];
}
void dfs_up(int v, int p, int w) {
dp_up[v] = min(INF, dp_up[p] + w);
if (dp[p].X.Y != v) dp_up[v] = min(dp[p].X.X + w, dp_up[v]);
if (dp[p].Y.Y != v) dp_up[v] = min(dp[p].Y.X + w, dp_up[v]);
if (B[v]) dp_up[v] = 0;
for (auto e : adj[v])
if (e.X != p)
dfs_up(e.X, v, e.Y);
}
ll Val(int v, int u) {
if (dp[v].X.Y != u) return dp[v].X.X;
else return dp[v].Y.X;
}
int Par(int v, int k) {
for (int i = LOG - 1; i >= 0; i--)
if (k & (1 << i))
v = par[v][i];
return v;
}
int LCA(int v, int u) {
if (H[v] < H[u]) swap(v, u);
v = Par(v, H[v] - H[u]);
if (v == u) return v;
for (int i = LOG - 1; i >= 0; i--)
if (par[v][i] != par[u][i])
v = par[v][i], u = par[u][i];
return par[v][0];
}
ll LD(int v, int k) {
int R = v;
if (k < 0) return INF;
ll ans = dp[v].X.X;
for (int i = LOG - 1; i >= 0; i--) {
if (k & (1 << i)) {
ans = min(ans, Down[v][i] + dist[R] - dist[v]);
v = par[v][i];
}
}
return ans;
}
ll UD(int v, int k) {
if (k <= 0) return INF;
ll ans = INF;
int R = Par(v, k);
for (int i = LOG - 1; i >= 0; i--) {
if (k & (1 << i)) {
ans = min(ans, Up[v][i] + dist[par[v][i]] - dist[R]);
v = par[v][i];
}
}
return ans;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n >> s >> q >> e;
for (int i = 0; i < n - 1; i++) {
int u, v, w;
cin >> u >> v >> w;
adj[u].push_back({v, w});
adj[v].push_back({u, w});
edges.push_back({u, v});
}
for (int i = 0; i < s; i++) {
int x;
cin >> x;
B[x] = true;
}
dp_up[0] = INF;
dp[0] = {{INF, INF}, {INF, INF}};
dfs(1, 0);
dfs_up(1, 0, 0);
for (int i = 0; i <= n; i++) Down[i][0] = min(dp[i].X.X, dp[par[i][0]].X.X + dist[i] - dist[par[i][0]]), Up[i][0] = Val(par[i][0], i);
for (int i = 1; i < LOG; i++) {
for (int v = 1; v <= n; v++) {
int p = par[v][i - 1];
par[v][i] = par[p][i - 1];
Down[v][i] = min(Down[v][i - 1], Down[p][i - 1] + dist[v] - dist[p]);
Up[v][i] = min(Up[p][i - 1], Up[v][i - 1] + dist[p] - dist[par[v][i]]);
}
}
while (q--) {
int r, v;
cin >> r >> v;
int e_v = edges[r - 1].X, e_u = edges[r - 1].Y;
if (H[e_v] < H[e_u]) swap(e_v, e_u);
if (SubG(e_v, v)) {
if (sub_g[e_v]) {
cout << "escaped" << endl;
continue;
}
ll ans = min(INF, LD(v, H[v] - H[e_v]));
if (ans >= INF) cout << "oo" << endl;
else cout << ans << endl;
continue;
}
if (!sub_g[e_v]) {
cout << "escaped" << endl;
continue;
}
int lca = LCA(e_u, v);
ll ans = dp_up[lca] + dist[v] - dist[lca];
ans = min(ans, UD(e_v, H[e_v] - H[lca]) + dist[v] - dist[lca]);
ans = min(ans, LD(v, H[v] - H[lca] - 1));
if (ans >= INF) cout << "oo" << endl;
else cout << ans << endl;
}
return 0;
}
