import sys N, K, INF, W = 10**5+5, 17, 10**18, 200 sys.setrecursionlimit(N) adj, cost = [[[] for i in range(N)] for j in range(2)] is_shop, depth, root_dist, shop_dist = [[0 for i in range(N)] for j in range(4)] st, par = [[[0 for i in range(N)] for j in range(K)] for k in range(2)] n, s, q, e = [int(_) for _ in input().split()] edges = [] def dfs(u, p = -1): shop_dist[u] = 0 if is_shop[u] else INF for i in range(len(adj[u])): v = adj[u][i] if v == p: continue par[0][v] = u depth[v] = depth[u]+1; root_dist[v] = root_dist[u]+cost[u][i] dfs(v,u) shop_dist[u] = min(shop_dist[u],shop_dist[v]+cost[u][i]) def get_block(ind): u,v = edges[ind-1] return u if depth[u] > depth[v] else v def prep_lca(): for u in range(1,n+1): st[0][u] = min(shop_dist[u],shop_dist[par[0][u]]) for s in range(1,K-1): for u in range(1,n+1): par[s][u] = par[s-1][par[s-1][u]] st[s][u] = min(st[s-1][u],st[s-1][par[s-1][u]]) def get_lca(u,v): if depth[u] < depth[v]: u,v = v,u for k in range(K-1,-1,-1): if depth[par[k][u]] >= depth[v]: u = par[k][u] if u == v: return u for k in range(K-1,-1,-1): if par[k][u] != par[k][v]: u, v = par[k][u], par[k][v] return par[0][u] def solve(u, block): lca = get_lca(u,block) if lca != block: return "escaped"; v = u ans = shop_dist[v] for k in range(K-1,-1,-1): if depth[par[k][v]] >= depth[block]: ans = min(ans,st[k][v]) v = par[k][v] if ans == INF: return "oo" return ans + root_dist[u] for i in range(n-1): a,b,w = [int(_) for _ in input().split()] adj[a].append(b) adj[b].append(a) cost[a].append(w) cost[b].append(w) edges.append([a,b]) for i in range(s): is_shop[int(input())] = True depth[e] = 1 dfs(e) for i in range(1,n+1): if shop_dist[i] != INF: shop_dist[i] -= root_dist[i] prep_lca() for i in range(q): ind,u = [int(x) for x in input().split()] block = get_block(ind) print(solve(u,block))