#include <iostream>
#include <vector>
#include <string>
#include <math.h>
#include <cmath>
#include <iomanip>
#include <cstdio>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <deque>
#include <bitset>
#include <cstring>
#include <unordered_map>
using namespace std;
typedef long long ll;
ll dep[100007];
vector<pair<ll, ll>> d[100007];
ll t[400007], mod[400007], buildby[400007];
bool shop[100007];
ll n, s, q, e;
void build(ll v, ll l, ll r){
if(l == r){
t[v] = buildby[l];
return;
}
ll mid = (l + r) >> 1;
build(2 * v, l, mid);
build(2 * v + 1, mid + 1, r);
t[v] = min(t[2 * v], t[2 * v + 1]);
}
void push(ll v, ll l, ll r){
if(mod[v] != 0 && l != r){
t[2 * v] += mod[v];
t[2 * v + 1] += mod[v];
mod[2 * v] += mod[v];
mod[2 * v + 1] += mod[v];
mod[v] = 0;
}
}
ll get(ll v, ll l, ll r, ll ql, ll qr){
if(r < ql || qr < l)
return (ll)(1e16);
if(ql <= l && r <= qr)
return t[v];
ll mid = (l + r) >> 1;
push(v, l, r);
return min(get(2 * v, l, mid, ql, qr), get(2 * v + 1, mid + 1, r, ql, qr));
}
ll get1(ll v, ll l, ll r, ll pos){
if(l == r)
return t[v];
ll mid = (l + r) >> 1;
push(v, l, r);
if(pos <= mid)
return get1(2 * v, l, mid, pos);
return get1(2 * v + 1, mid + 1, r, pos);
}
void update(ll v, ll l, ll r, ll ql, ll qr, ll val){
if(r < ql || qr < l)
return;
if(ql <= l && r <= qr){
t[v] += val;
mod[v] += val;
return;
}
ll mid = (l + r) >> 1;
push(v, l, r);
update(2 * v, l, mid, ql, qr, val);
update(2 * v + 1, mid + 1, r, ql, qr, val);
t[v] = min(t[2 * v], t[2 * v + 1]);
}
ll time_in[100007], time_out[100007];
ll step = 0;
void dfs(ll v, ll par){
time_in[v] = ++step;
for(auto i: d[v]){
if(i.first != par){
dep[i.first] = dep[v] + i.second;
dfs(i.first, v);
}
}
time_out[v] = step;
}
bool ispar(ll a, ll b){
return time_in[a] <= time_in[b] && time_in[b] <= time_out[a];
}
vector<pair<ll, ll>> quer[100007];
vector<pair<ll, ll>> edges;
string ans[100007];
void dfs2(ll v, ll par){
for(auto p: quer[v]){
pair<ll, ll> i = edges[p.first - 1];
if(ispar(i.second, v)){
update(1, 1, n, 1, n, (ll)(1e16));
update(1, 1, n, time_in[i.second], time_out[i.second], -(ll)(1e16));
}
else{
update(1, 1, n, time_in[i.second], time_out[i.second], (ll)(1e16));
}
// for(int j = 1; j <= n; j++)
// cout << get1(1, 1, n, time_in[j]) << ' ';
// cout << endl;
ll val = get1(1, 1, n, time_in[e]);
if(val < (ll)(1e16)){
ans[p.second] = "escaped";
}
else{
ll h = get(1, 1, n, 1, n);
if(h < (ll)(1e16))
ans[p.second] = to_string(h);
else
ans[p.second] = "oo";
}
if(ispar(i.second, v)){
update(1, 1, n, 1, n, -(ll)(1e16));
update(1, 1, n, time_in[i.second], time_out[i.second], (ll)(1e16));
}
else{
update(1, 1, n, time_in[i.second], time_out[i.second], -(ll)(1e16));
}
}
for(auto i: d[v]){
if(i.first != par){
update(1, 1, n, 1, n, i.second);
update(1, 1, n, time_in[i.first], time_out[i.first], -2 * i.second);
dfs2(i.first, v);
update(1, 1, n, 1, n, -i.second);
update(1, 1, n, time_in[i.first], time_out[i.first], 2 * i.second);
}
}
}
int main(){
cin >> n >> s >> q >> e;
for(int i = 0; i < n - 1; i++){
ll a, b, c;
cin >> a >> b >> c;
edges.push_back({a, b});
d[a].push_back({b, c});
d[b].push_back({a, c});
}
for(int i = 0; i < s; i++){
ll c;
cin >> c;
shop[c] = true;
}
dfs(1, -1);
// fill in buildby
for(int i = 1; i <= n; i++){
if(!shop[i] && i != e){
buildby[time_in[i]] = dep[i] + (ll)(1e16);
continue;
}
buildby[time_in[i]] = dep[i];
}
build(1, 1, n);
for(auto &i: edges){
if(dep[i.first] > dep[i.second])
swap(i.first, i.second);
}
for(int i = 0; i < q; i++){
ll e, v;
cin >> e >> v;
quer[v].push_back({e, i});
}
dfs2(1, -1);
for(int i = 0; i < q; i++)
cout << ans[i] << endl;
return 0;
}
