#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define ull unsigned long long
#define bigint __int128
#define pb push_back
#define emb emplace_back
#define pii pair <int, int>
#define fi first
#define se second
#define Task ""
#define testBit(n, k) ((n >> k) & 1)
#define flipBit(n, k) (n ^ (1ll << k))
template <class T> void minimize(T &a, T b) {if (a > b) a = b;}
template <class T> void maximize(T &a, T b) {if (a < b) a = b;}
const int N = 1e5 + 3, LG = 17, mod = 1e9 + 7;
const ll INF = 1e18;
int n, s, q, h;
vector <int> adj[N];
bitset <N> food;
struct Edge {
int u, v, w;
} e[N];
namespace sub2 {
ll dist[1005]; ll ans; int del_id;
void dfs(int u, int p) {
if (food.test(u)) minimize(ans, dist[u]);
for (int id: adj[u]) {
int v = u ^ e[id].u ^ e[id].v, w = e[id].w;
if (v == p || id == del_id) continue;
dist[v] = dist[u] + w;
dfs(v, u);
}
}
void solve() {
while (q--) {
int r; cin >> del_id >> r;
memset(dist, -1, sizeof dist);
dist[r] = 0; ans = INF;
dfs(r, 0);
if (dist[h] != -1) cout << "escaped\n";
else if (ans == INF) cout << "oo\n";
else cout << ans << '\n';
}
}
}
namespace sub4 {
int dep[N], low[N], tail[N], dfsTimes = 0; // min dis in subtree
ll opt[N], dist[N];
void dfs(int u, int p) {
low[u] = ++dfsTimes;
if (food.test(u)) opt[u] = 0;
for (int id: adj[u]) {
int v = u ^ e[id].u ^ e[id].v, w = e[id].w;
if (v == p) continue;
dep[v] = dep[u] + 1;
dist[v] = dist[u] + w;
dfs(v, u);
minimize(opt[u], opt[v] + w);
}
tail[u] = dfsTimes;
}
bool ancestor(int u, int v) { // u is parent of v
return low[u] <= low[v] && tail[v] <= tail[u];
}
ll st[N][LG];
int up[N][LG];
void calc(int u, int p) {
for (int id: adj[u]) {
int v = u ^ e[id].u ^ e[id].v, w = e[id].w;
if (v == p) continue;
up[v][0] = u;
st[v][0] = -dist[u] + opt[u];
for (int i = 1; i < LG; i++) {
up[v][i] = up[up[v][i - 1]][i - 1];
st[v][i] = min(st[v][i - 1], st[up[v][i - 1]][i - 1]);
}
calc(v, u);
}
}
void solve() { // dist[r] - dist[p] + opt[p]
memset(opt, 0x3f, sizeof opt);
dfs(h, 0); calc(h, 0);
while (q--) {
int i, r; cin >> i >> r;
int u = e[i].u, v = e[i].v;
if (dep[u] > dep[v]) swap(u, v);
if (!ancestor(v, r)) cout << "escaped\n";
else {
ll ans = opt[r]; int cur = r;
for (int i = 0, k = dep[r] - dep[v]; (1 << i) <= k; i++)
if (testBit(k, i)) {
minimize(ans, dist[r] + st[cur][i]);
cur = up[cur][i];
}
if (ans >= INF) cout << "oo\n";
else cout << ans << '\n';
}
}
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
if(fopen(Task".inp", "r")) {
freopen(Task".inp", "r", stdin);
freopen(Task".out", "w", stdout);
}
cin >> n >> s >> q >> h;
for (int i = 1; i < n; i++) {
int u, v, w; cin >> u >> v >> w;
adj[u].emb(i); adj[v].emb(i);
e[i] = {u, v, w};
}
for (int i = 0; i < s; i++) {
int u; cin >> u; food.set(u);
}
sub4::solve();
}
