#include <bits/stdc++.h>
using namespace std;
const int maxN = 1e5 + 5; const long long inf = 1e18;
long long dis[maxN], spec[maxN], jp[20][maxN];
int par[20][maxN], in[maxN], out[maxN], sus[maxN], pos[maxN], timeDfs = 0;
vector<pair<int, int>> adj[maxN];
struct tmp {
int u, v, w;
} edge[maxN];
void dfs(int u, int pre) {
in[u] = ++timeDfs;
pos[timeDfs] = u;
for (auto it: adj[u]) {
int v = it.first, w = it.second;
if (v == pre) continue;
dis[v] = dis[u] + w;
par[0][v] = u;
dfs(v, u);
}
out[u] = timeDfs;
}
long long st[4 * maxN];
void build(int id, int l, int r) {
if (l == r) {
if (sus[pos[l]]) st[id] = dis[pos[l]];
else st[id] = inf;
return ;
}
int mid = (l + r) >> 1;
build(2 * id, l, mid);
build(2 * id + 1, mid + 1, r);
st[id] = min(st[2 * id], st[2 * id + 1]);
}
long long get(int id, int l, int r, int u, int v) {
if (v < l || r < u) return inf;
if (u <= l && r <= v) return st[id];
int mid = (l + r) >> 1;
long long A = get(2 * id, l, mid, u, v);
long long B = get(2 * id + 1, mid + 1, r, u, v);
return min(A, B);
}
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n, s, q, root;
cin >> n >> s >> q >> root;
for (int i = 1; i < n; i++) {
int u, v, w;
cin >> u >> v >> w;
edge[i] = {u, v, w};
adj[u].push_back({v, w});
adj[v].push_back({u, w});
}
for (int i = 1; i <= s; i++) {
int x; cin >> x;
sus[x] = 1;
}
dfs(root, root);
build(1, 1, n);
for (int i = 1; i <= n; i++) {
spec[i] = inf;
long long len = get(1, 1, n, in[i], out[i]);
if (len != inf) spec[i] = len - dis[i] * 2;
}
for (int i = 1; i <= n; i++)
jp[0][i] = spec[par[0][i]];
for (int k = 1; k <= 16; k++) {
for (int i = 1; i <= n; i++) {
par[k][i] = par[k - 1][par[k - 1][i]];
jp[k][i] = min(jp[k - 1][i], jp[k - 1][par[k - 1][i]]);
}
}
for (int i = 1; i < n; i++)
if (in[edge[i].u] > in[edge[i].v]) swap(edge[i].u, edge[i].v);
while (q--) {
int id, u;
cin >> id >> u;
int p = edge[id].v;
if (!(in[p] <= in[u] && out[u] <= out[p])) {
cout << "escaped\n";
continue;
}
long long ans = inf, org = dis[u];
ans = min(ans, spec[u]);
for (int k = 16; k >= 0; k--) {
int v = par[k][u];
if (in[p] <= in[v]) {
ans = min(ans, jp[k][u]);
u = v;
}
}
if (ans == inf) cout << "oo\n";
else cout << ans + org << '\n';
}
return 0;
}
