#include<bits/stdc++.h>
using namespace std;
#define LIFESUCKS ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ll long long
#define pb push_back
#define fi first
#define se second
#define debug cout<<"I Love You\n";
#define Bitc(x, j) ((x >> j) & 1)
#define fu(i,a,b) for ( int i = a; i <= b; i++ )
#define fd(i,b,a) for ( int i = b; i >= a; i-- )
const ll Mod = 1e9+7;
const ll inf = 1e15;
const ll lnf = (1ll << 60);
template <class X, class Y>
bool minimize (X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize (X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
#define mxn 100007
int numNode, numShop, numQuest, nodeExit;
int shop[mxn];
int h[mxn], g[mxn], uwu[mxn];
ll f[19][mxn], d[19][mxn], node[19][mxn];
ll shortShop[mxn];
vector<pair<int,ll>> graph[mxn];
struct Edge{
ll u, v, w;
} edge[mxn];
void dfs ( ll u, ll p ) {
for ( auto & [v, w]: graph[u] ) {
if ( v == p ) continue;
h[v] = h[u] + 1;
g[v] = g[u] + w;
dfs ( v, u );
minimize ( shortShop[u], shortShop[v] + w );
}
}
void dfs2 ( ll u ) {
for ( auto& [v, w]: graph[u] ) {
if ( v == f[0][u] ) continue;
f[0][v] = u;
node[0][v] = u;
d[0][v] = shortShop[u];
if ( minimize( d[0][v], shortShop[v] ) ) node[0][v] = v;
fu ( j, 1, 17 ) {
f[j][v] = f[j-1][f[j - 1][v]];
node[j][v] = node[j - 1][v];
d[j][v] = d[j - 1][v];
if ( d[j][v] > d[j - 1][f[j - 1][v]] ) {
d[j][v] = d[j - 1][f[j - 1][v]];
node[j][v] = node[j - 1][f[j - 1][v]];
}
}
dfs2(v);
}
}
ll lca ( ll u, ll v ) {
if ( h[u] < h[v] ) swap ( u, v );
ll k = h[u] - h[v];
fu ( j, 0, 17 ) if ( Bitc(k, j)) u = f[j][u];
if ( u == v ) return u;
fd ( j, 17, 0 ) if ( f[j][u] != f[j][v] ) u = f[j][u], v = f[j][v];
return f[0][u];
}
void lovesper(const ll TestCase){
cin >> numNode >> numShop >> numQuest >> nodeExit;
fu ( i, 2, numNode){
ll u, v, w;cin >> u >> v >> w;
graph[u].pb({ v, w });
graph[v].pb({ u, w });
edge[i - 1] = { u, v, w };
}
memset( shortShop, 0x3f, sizeof(shortShop));
fu ( i, 1, numShop ) {
ll x;cin >> x;
shop[x] = 1;
shortShop[x] = 0;
}
memset( d, 0x3f, sizeof(d));
dfs( nodeExit, 0 );
dfs2(nodeExit);
// fu ( i, 1, numNode ) cout << i << ' ' << shortShop[i] << '\n';
fu ( i, 2, numNode ){
auto&[ u, v, w ] = edge[i - 1];
if ( h[u] > h[v] ) swap ( u, v );
}
fu ( qst, 1, numQuest ) {
ll i, s;cin >> i >> s;
// cout << '\n';
// fu ( x, 1, numNode - 1 ) {
// auto [ aa, bb , cc ] = edge[x];
// cout << aa << ' ' << bb << ' ' << cc << '\n';
// }
auto [ u, v, w ] = edge[i];
ll p = lca ( s, v );
if ( v == p ) {
ll sad = shortShop[s];
ll t, a = s, cr = lnf;
if ( shortShop[v] >= 4557430888798830399 ) {
cout << "oo" << '\n';
continue;
}
if ( s == v ) {
cout << shortShop[v] <<'\n';
continue;
}
ll k = h[s] - h[v] - ( shop[v] ) ;
// cout << k << '\n';
fu ( j, 0, 17 ) {
if ( !Bitc(k, j)) continue;
if ( minimize(cr, d[j][a] )) t = node[j][a];
// cout << a << ' ' << d[j][a] << '\n';
a = f[j][a];
}
minimize ( sad, shortShop[t] + ( g[s] - g[t] ));
if ( shop[v] ) minimize ( sad, abs(g[s] - g[v]) );
if ( shop[f[0][s]] ) minimize ( sad, abs( g[s] - g[f[0][s]] ) );
// cout << t << '\n';
//// cout << cr << '\n';
// cout << shortShop[t] << ' ' << g[s] - g[t] << '\n';
cout << sad << '\n';
// cout << '\n';
} else cout << "escaped\n";
}
}
signed main(){
LIFESUCKS
#define name "lovesper"
freopen(name".test", "r", stdin);
freopen(name".out", "w", stdout);
ll test=1;
// cin >> test;
for (int i = 1; i <= test; i++){
lovesper(i);
if ( i < test ) cout << '\n';
}
return 0;
}
