// Om Namah Shivaya
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a, b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a, b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
*/
const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
vector<array<ll, 3>> adj[N];
vector<array<ll, 3>> edges(N);
vector<ll> edge_node(N);
vector<ll> tin(N), tout(N);
ll timer = 1;
void dfs(ll u, ll p) {
tin[u] = timer++;
for (auto [v, w, id] : adj[u]) {
if (v == p) conts;
edge_node[id] = v;
dfs(v, u);
}
tout[u] = timer++;
}
void solve(int test_case)
{
ll n, s, q; cin >> n >> s >> q;
ll des; cin >> des;
rep1(i, n - 1) {
ll u, v, w; cin >> u >> v >> w;
edges[i] = {u, v, w};
adj[u].pb({v, w, i}), adj[v].pb({u, w, i});
}
vector<ll> spl(s + 5);
rep1(i, s) cin >> spl[i];
dfs(des, -1);
while (q--) {
ll edge, src; cin >> edge >> src;
ll sub = edge_node[edge];
ll l = tin[sub], r = tout[sub];
if (!(tin[src] >= l and tout[src] <= r)) {
cout << "escaped" << endl;
}
else if (s == n) {
cout << 0 << endl;
}
else {
queue<ll> q;
vector<bool> vis(n + 5);
vector<ll> dis(n + 5, inf2);
q.push(src);
vis[src] = 1;
dis[src] = 0;
while (!q.empty()) {
ll u = q.front();
q.pop();
for (auto [v, w, id] : adj[u]) {
if (id == edge) conts;
if (vis[v]) conts;
q.push(v);
vis[v] = 1;
dis[v] = dis[u] + w;
}
}
ll ans = inf2;
rep1(j, s) amin(ans, dis[spl[j]]);
if (ans < inf2) cout << ans << endl;
else cout << "oo" << endl;
}
}
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
