#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];
const int K = 17;
ll st[K][N];
int par[K][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;
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]);
}
}
int n,e;
vl path;
const int W = 300;
int up_by_w[N];
void opti(int u, int p = -1){
while(st[0][u] != e && shop_dist[st[0][u]] >= shop_dist[u]){
int w = up_by_w[st[0][u]];
if(w != e && shop_dist[w] >= shop_dist[u])
st[0][u] = w;
else
st[0][u] = st[0][st[0][u]];
}
up_by_w[u] = st[0][u];
for(int i = 0; i < W; ++i)
up_by_w[u] = st[0][up_by_w[u]];
for(int i = 0; i < sz(adj[u]); ++i){
int v = adj[u][i];
if(v == p) continue;
st[0][v] = u;
opti(v,u);
}
}
void prep_st(){
st[0][e] = e;
opti(e);
for(int s = 1; s < K; ++s)
for(int u = 1; u <= n; ++u)
st[s][u] = st[s-1][st[s-1][u]];
}
vpii edges;
int get_block(int id){
int u,v;
tie(u,v) = edges[id-1];
return depth[u] > depth[v] ? u : v;
}
void prep_lca(){
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";
int v = u;
for(int s = K-1; s >= 0; --s)
if(depth[st[s][v]] >= depth[block])
v = st[s][v];
if(shop_dist[v] == INF)
return "oo";
return to_string(shop_dist[v]+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_st();
prep_lca();
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);
_();
}
