// Source: https://usaco.guide/general/io #include <bits/stdc++.h> using namespace std; using ll = long long; const ll cap = 1e2+1; vector<pair<ll,ll>> adj[cap]; void dijkstra(){ } int main() { ios::sync_with_stdio(0); cin.tie(0); ll n, s, q, e; cin >> n >> s >> q >> e; vector<tuple<ll,ll,ll>> edges; for (ll i{}; i < n-1; i++){ ll a, b, w; cin >> a >> b >> w; adj[a].push_back({b,w}); adj[b].push_back({a,w}); edges.push_back({a,b,w}); } vector<ll> shops; for (ll i{}; i < s; i++){ ll c; cin >> c; shops.push_back(c); } for (ll i{}; i < q; i++){ ll I, r; cin >> I >> r; ll a, b, w; tie(a, b, w) = edges[I-1]; erase(adj[a], make_pair(b, w)); erase(adj[b], make_pair(a, w)); priority_queue<pair<ll,ll>> pq; vector<bool> visited(n+1, false); vector<ll> dist(n+1, 1e18); dist[r] = 0; pq.push({0, r}); while (!pq.empty()){ auto t = pq.top(); pq.pop(); ll d = -t.first; ll v = t.second; if (visited[v]) continue; visited[v] = true; for (auto pr : adj[v]){ ll u = pr.first; ll wt = pr.second; if (dist[u] > d + wt){ dist[u] = d + wt; pq.push({-dist[u], u}); } } } if (dist[e] == 1e18) { ll ans = 1e18; for (ll v : shops) { ans = min(ans, dist[v]); } if (ans == 1e18) { cout << "oo\n"; } else { cout << ans << "\n"; } } else { cout << "escaped\n"; } adj[a].push_back({b,w}); adj[b].push_back({a,w}); } }