////!pragma
//const int N = 1e5+5;
//vl adj[N],cost[N];
//ll depth[N],root_dist[N],shop_dist[N],dir_par[N];
//bool is_shop[N];
//void dfs(int u, int p = -1){
// shop_dist[u] = is_shop[u] ? 0 : INF;
// for(int i = 0; i < sz(adj[u]); ++i){
// int v = adj[u][i];
// if(v == p) continue;
// dir_par[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]);
// }
//}
//int n,e;
//const int W = 150;
//ll cheat_up[N], cheat_w[N];
//vl rdfs_order;
//void opti(int u, int p = -1){
// while(cheat_up[u] != e && shop_dist[cheat_up[u]] >= shop_dist[u])
// cheat_up[u] = cheat_up[cheat_up[u]];
// for(int i = 0; i < sz(adj[u]); ++i){
// int v = adj[u][i];
// if(v == p) continue;
// cheat_up[v] = u;
// opti(v,u);
// }
//}
//void prep_cheat(){
// cheat_up[e] = e;
// opti(e);
// for(int i = 1; i <= n; ++i){
// cheat_w[i] = cheat_up[i];
// for(int j = 0; j < W; ++j)
// cheat_w[j] = cheat_up[cheat_w[j]];
// }
//}
//vpii edges;
//int get_block(int id){
// int u,v;
// tie(u,v) = edges[id-1];
// return depth[u] > depth[v] ? u : v;
//}
//const int K = 17;
//int par[K][N];
//void lca_prep(){
// for(int u = 1; u <= n; ++u)
// par[0][u] = dir_par[u];
// for(int s = 1; s < K; ++s)
// for(int u = 1; u <= n; ++u)
// par[s][u] = par[s-1][par[s-1][u]];
//}
//int get_lca(int u, int v){
// if(depth[u] < depth[v])
// swap(u,v);
// for(int k = K-1; k >= 0; --k)
// if(depth[par[k][u]] >= depth[v])
// u = par[k][u];
// if(u == v)
// return u;
// for(int k = K-1; k >= 0; --k)
// if(par[k][u] != par[k][v]){
// u = par[k][u];
// v = par[k][v];
// }
// return par[0][u];
//}
//string solve(int u, int block){
// //first part: correct: can we escape?
// int lca = get_lca(u,block);
// if(lca != block)
// return "escaped";
// //watch(u);
// //watch(block);
// //watch(lca);
// //second part: cheating, TODO: find a test to break this
// ll ans = INF;
// for(int v = u; ;){
// if(depth[v] < depth[block])
// break;
// if(shop_dist[v] != INF)
// ans = min(ans,shop_dist[v]);
// if(depth[cheat_w[v]] >= depth[block]){
// v = cheat_w[v];
// }
// else
// v = cheat_up[v];
// }
// if(ans == INF) return "oo";
// return to_string(ans+root_dist[u]);
//}
//void _(){
// int s,q;
// cin >> n >> s >> q >> e;
// for(int i = 0; i < n-1; ++i){
// int a,b,w;
// cin >> a >> b >> w;
// adj[a].pb(b);
// adj[b].pb(a);
// cost[a].pb(w);
// cost[b].pb(w);
// edges.pb({a,b});
// }
// for(int i = 0; i < s; ++i){
// int u;
// cin >> u;
// is_shop[u] = true;
// }
// depth[e] = 1;
// dfs(e);
// for(int i = 1; i <= n; ++i)
// if(shop_dist[i] != INF)
// shop_dist[i] -= root_dist[i];
// prep_cheat();
// lca_prep();
// //watch(root_dist[3]);
// //watch(shop_dist[3]);
// //watch(root_dist[5]);
// for(int i = 0; i < q; ++i){
// int id,u;
// cin >> id >> u;
// int block = get_block(id);
// print(solve(u,block));
// }
//}
#pragma GCC optimize("Ofast")
#include <stack>
#include <iomanip>
#include <algorithm>
#include <cassert>
#include <vector>
#include <utility>
#include <iostream>
#include <string>
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define sz(v) ll(v.size())
#define T1 template<typename T> static
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
const ll INF = ll(2e18) + 666;
T1 ostream& operator<<(ostream& stream, const vector<T>& t);
T1 void print(T x, string end = "\n"){
cout << x << end;
}
//!pragma
const int N = 1e5+5;
vl adj[N],cost[N];
ll depth[N],root_dist[N],shop_dist[N],dir_par[N];
bool is_shop[N];
void dfs(int u, int p = -1){
shop_dist[u] = is_shop[u] ? 0 : INF;
for(int i = 0; i < sz(adj[u]); ++i){
int v = adj[u][i];
if(v == p) continue;
dir_par[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]);
}
}
int n,e;
const int W = 250;
ll cheat_up[N], cheat_w[N];
int up_by_w[N];
void opti(int u, int p = -1){
while(cheat_up[u] != e && shop_dist[cheat_up[u]] >= shop_dist[u]){
int w = up_by_w[cheat_up[u]];
if(w != e && shop_dist[w] >= shop_dist[u])
cheat_up[u] = w;
else
cheat_up[u] = cheat_up[cheat_up[u]];
}
up_by_w[u] = cheat_up[u];
for(int i = 0; i < W; ++i)
up_by_w[u] = cheat_up[up_by_w[u]];
for(int i = 0; i < sz(adj[u]); ++i){
int v = adj[u][i];
if(v == p) continue;
cheat_up[v] = u;
opti(v,u);
}
}
void prep_cheat(){
cheat_up[e] = e;
opti(e);
for(int i = 1; i <= n; ++i){
cheat_w[i] = cheat_up[i];
for(int j = 0; j < W; ++j)
cheat_w[i] = cheat_up[cheat_w[i]];
}
}
vpii edges;
int get_block(int id){
int u,v;
tie(u,v) = edges[id-1];
return depth[u] > depth[v] ? u : v;
}
const int K = 17;
int par[K][N];
void lca_prep(){
for(int u = 1; u <= n; ++u)
par[0][u] = dir_par[u];
for(int s = 1; s < K; ++s)
for(int u = 1; u <= n; ++u)
par[s][u] = par[s-1][par[s-1][u]];
}
int get_lca(int u, int v){
if(depth[u] < depth[v])
swap(u,v);
for(int k = K-1; k >= 0; --k)
if(depth[par[k][u]] >= depth[v])
u = par[k][u];
if(u == v)
return u;
for(int k = K-1; k >= 0; --k)
if(par[k][u] != par[k][v]){
u = par[k][u];
v = par[k][v];
}
return par[0][u];
}
string solve(int u, int block){
int lca = get_lca(u,block);
if(lca != block)
return "escaped";
ll ans = INF;
for(int v = u; ;){
if(depth[v] < depth[block])
break;
while(depth[cheat_w[v]] >= depth[block]){
//cerr << "called: " << depth[v] << ' ' << depth[cheat_w[v]] << '\n';
v = cheat_w[v];
}
if(shop_dist[v] != INF)
ans = min(ans,shop_dist[v]);
v = cheat_up[v];
}
if(ans == INF) return "oo";
return to_string(ans+root_dist[u]);
}
void _(){
int s,q;
cin >> n >> s >> q >> e;
for(int i = 0; i < n-1; ++i){
int a,b,w;
cin >> a >> b >> w;
adj[a].pb(b);
adj[b].pb(a);
cost[a].pb(w);
cost[b].pb(w);
edges.pb({a,b});
}
for(int i = 0; i < s; ++i){
int u;
cin >> u;
is_shop[u] = true;
}
depth[e] = 1;
dfs(e);
for(int i = 1; i <= n; ++i)
if(shop_dist[i] != INF)
shop_dist[i] -= root_dist[i];
prep_cheat();
lca_prep();
//cerr << "prep done\n";
//watch(root_dist[3]);
//watch(shop_dist[3]);
//watch(root_dist[5]);
for(int i = 0; i < q; ++i){
int id,u;
cin >> id >> u;
int block = get_block(id);
print(solve(u,block));
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout << fixed << setprecision(15);
_();
}
