#include <algorithm> #include <array> #include <bitset> #include <cassert> #include <chrono> #include <climits> #include <cmath> #include <cstdint> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #include <functional> #include <fstream> #include <iomanip> #include <iostream> #include <map> #include <numeric> #include <queue> #include <random> #include <stack> #include <string> #include <set> #include <thread> #include <type_traits> #include <unordered_set> #include <utility> #include <vector> using namespace std; using namespace __gnu_pbds; #define pb push_back #define fast() \ ios_base::sync_with_stdio(false); \ cin.tie(NULL); #define F(i, l, r) for (int i = l; i < l + r; i++) #define all(v) v.begin(), v.end() #define allr(v) v.rbegin(), v.rend() #define PI acos(-1) #define bit_len(n) (n?(64 - __builtin_clzll(n)):0) #define bit_count(n) __builtin_popcountll(n) #define yes(i) cout << (i ? "Yes" : "No") << endl; #define X first #define Y second #define sz(v) (int)(v).size() #define vvl(x, n, m, val) vector<vector<ll>> x(n, vector<ll>(m, val)) #define bb __int128_t typedef long long ll; typedef std::pair<int, int> pi; ll inf_ll = 1e18; const ll inf = 1e8; typedef long double ld; typedef pair<ll, ll> pll; typedef vector<int> vi; typedef vector<vi> vvi; typedef vector<ll> vll; typedef vector<bool> vb; typedef vector<string> vs; typedef vector<pll> vp; mt19937_64 mt(727); uniform_int_distribution<ll> uni(1, inf / 2); const int Mod[] = {998244353, (int)1e9 + 7}; const int mod = Mod[1]; const int max_n = 1e6 + 5; const int N = 2e5+5; vi dr = {-1, 1, 0, 0}; vi dc = {0, 0, -1, 1}; string dir = "DURL"; bool pow(bb a, int n, ll lim) { bb m = 1; for (int i = 1; i <= n; i++) { m = m * a; if (m > lim) { return false; } } return true; } ll ncr(ll n, ll k) { if (n < k) return 0; if (n < 0 || k < 0) return 0; k = min(k, n - k); ll res = 1; F(i, 0, k) { res = (ll)(res * (n - i)); res = (ll)res / (i + 1); } return res; } int sqr(ll x) { ll l = 0, r = x; int val = 0; while (l <= r) { ll m = (l + r) / 2; if (m * m >= x) { r = m - 1; val = m; } else l = m + 1; } return val; } void chmin(int &a, int b) { a = min(a, b); } void chmax(int &a, int b) { a = max(a, b); } // LCA by binary lifting O(NlogN) precomp and O(logN) per query const int l = 20; vi adj[N]; vi depth(N); int timer = 0; vi in(N), out(N); int up[N][20]; void dfs(int u, int p) { timer++; in[u] = timer; up[u][0] = p; for (int j = 1; j < l; j++) { up[u][j] = up[up[u][j - 1]][j - 1]; } for (auto v: adj[u]) { if (v != p) { depth[v] = 1 + depth[u]; dfs(v, u); } } out[u] = ++timer; } //checks if a is an ancestor of b bool is_anc(int a, int b) { return (in[a] <= in[b] && out[a] >= out[b]); } int lca(int u, int v) { if (is_anc(u, v)) { return u; } if (is_anc(v, u)) { return v; } for (int j = l - 1; j >= 0; j--) { if (!is_anc(up[u][j], v)) { u = up[u][j]; } } return up[u][0]; } void solve() { int n, s, q, e; cin >> n >> s >> q >> e; vector<array<int,4>>ed(n-1); for (int i = 0; i < n-1; i++) { int u, v, w; cin >> u >> v >> w; u--, v--; adj[u].pb(v); adj[v].pb(u); ed[i] = {u, v, w, i}; } e--; for (int j = 0; j < l; j++) { up[e][j] = e; } dfs(e, e); vector<ll>wt(n); vector<int>ind(n-1); for (auto [u, v, w, i] : ed) { int put = u; if (depth[u] < depth[v]) { put = v; } wt[put] = w; ind[i] = put; } vector<ll>sum(n); vector<ll>path(n, inf_ll); vector<bool>shop(n); for (int i = 0; i < s; i++) { int x; cin >> x; x--; shop[x] = true; } function<void(int,int)>dfs1=[&](int u, int p) { if (shop[u]) { path[u] = sum[u]; } for (int v : adj[u]) { if (v != p) { sum[v] = sum[u] + wt[v]; dfs1(v, u); path[u] = min(path[u], path[v]); } } }; dfs1(e, e); vector<vector<ll>>jump(n, vector<ll>(l, inf_ll)); for (int i = 0; i < n; i++) { if (path[i]!=inf_ll) { path[i] -= 2*sum[i]; for (int j = 0; j < l; j++) { jump[i][j] = path[i]; } } } function<void(int,int)>build=[&](int u, int p) { jump[u][0] = min(path[p], path[u]); for (int j = 1; j < l; j++) { jump[u][j] = min(jump[u][j-1], jump[up[u][j-1]][j-1]); } for (int v : adj[u]) { if (v != p) { build(v, u); } } }; build(e, e); while (q--) { int i, r; cin >> i >> r; i--; r--; int x = ind[i]; if (lca(x, r)!=x) { cout << "escaped\n"; continue; } int curr = r; ll ans = path[r]; int dist = depth[r] - depth[x]; for (int j = 0; j < l; j++) { if (dist&(1<<j)) { ans = min(ans, jump[curr][j]); curr = up[curr][j]; } } if (ans == inf_ll) { cout << "oo\n"; } else { cout << ans + sum[r] << "\n"; } } } int main() { fast() /*freopen("cowland.in", "r", stdin); freopen("cowland.out", "w", stdout);*/ cout << setprecision(10) << fixed; int tt = 1; auto begin = std::chrono::high_resolution_clock::now(); while (tt--) { solve(); } /*auto end = std::chrono::high_resolution_clock::now(); auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin); cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n";*/ return 0; }