#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
#define fio ios_base::sync_with_stdio(0);cin.tie(0);
#define ll long long
#define ld long double
#define en exit(0);
#define pb push_back
#define fi first
#define se second
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e5 + 5;
const ll INF = 1e18 + 5;
vector<pair<int,int> > edg;
int w[N];
bool shop[N];
int main()
{
fio
// ifstream cin("in.in");
int n, s, q, e;
cin >> n >> s >> q >> e;
edg.resize(n - 1);
for(int i = 0;i < n - 1;i++)
{
int u, v;
cin >> u >> v;
if(u > v)
swap(u, v);
cin >> w[u];
edg[i] = {u, v};
}
for(int i = 1;i <= s;i++)
{
int p;
cin >> p;
shop[p] = 1;
}
while(q--)
{
int i, r;
cin >> i >> r;
int u = edg[i - 1].fi, v = edg[i - 1].se;
if(u > v)
swap(u, v);
ll best = INF, cur = 0;
if(r == e)
best = -1;
if(shop[r])
best = 0;
if(r != u)
{
for(int i = r + 1;i <= n;i++)
{
cur += w[i - 1];
if(shop[i])
best = min(best, cur);
if(i == e)
best = -1;
if(i == u)
break;
}
}
if(r != v)
{
cur = 0;
for(int i = r - 1;i >= 1;i--)
{
cur += w[i];
if(shop[i])
best = min(best, cur);
if(i == e)
best = -1;
if(i == v)
break;
}
}
if(best == -1)
cout << "escaped";
else if(best == INF)
cout << "oo";
else
cout << best;
cout << "\n";
}
return 0;
}
