// #include <bits/stdc++.h> #include <iostream> #include <cmath> #include <algorithm> #include <map> #include <unordered_map> #include <vector> #include <iomanip> #include <string> #include <queue> #include <set> #include <deque> using namespace std; #define endl "\n" #define pb push_back #define int long long #define fi first #define se second const int N = 3e5 + 5, M = 1e9 + 7, LG = 20; int n , A[N] , u , v , w , q , e , s , x , P[N] , dp[N] , I[N] , in = 1 , U[N] , V[N] , O[N] , sp[N][LG] , dep[N] , pr[N][LG]; bool vi[N]; vector<pair<int,int>> lis[N]; void dfs(int v , int par , int wi){ P[v] = par; dp[v] = 1e18; dep[v] = dep[par] + wi; I[v] = in; in++; for (auto [u,w] : lis[v]){ if (u == par) continue; dfs(u , v , w); dp[v] = min(dp[v] , dp[u]); } if (vi[v]){ dp[v] = dep[v]; } sp[v][0] = dp[v] - 2 * dep[v]; pr[v][0] = v; O[v] = in; in++; } void solve(){ cin >> n >> s >> q >> e; dp[0] = 1e18; for (int i=1 ; i<n ; i++){ cin >> u >> v >> w; lis[u].pb({v,w}); lis[v].pb({u,w}); U[i] = u; V[i] = v; } for (int i=1 ; i<=s ; i++){ cin >> x; vi[x] = 1; } dfs(e , 0 , 0); for (int j=1 ; j<LG ; j++){ for (int i=1 ; i<=n ; i++){ pr[i][j] = pr[P[pr[i][j-1]]][j-1]; } } for (int j=1 ; j<LG ; j++){ for (int i=1 ; i<=n ; i++){ if (!pr[i][j]) continue; sp[i][j] = min(sp[i][j-1] , sp[P[pr[i][j-1]]][j-1]); } } while(q--){ cin >> x >> v; int u = -1; if (P[U[x]] == V[x]){ u = U[x]; }else{ u = V[x]; } if (I[v] >= I[u] && O[v] <= O[u]){ int ans = 1e18 , v1 = v; for (int i=LG-1 ; i>=0 ; i--){ if (!pr[v][i]) continue; int j = pr[v][i]; if (I[j] >= I[u] && O[j] <= O[u]){ ans = min(ans , sp[v][i]); v = pr[v][i]; } } ans += dep[v1]; if (ans >= 1e15){ cout << "oo" << endl; }else{ cout << ans << endl; } }else{ cout << "escaped" << endl; } } } signed main(){ // freopen("" , "r" , stdin); // freopen("" , "w" , stdout); // cout << setprecision(30); ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); int ts = 1; // cin >> ts; while(ts--){ solve(); } }