#include <bits/stdc++.h>
#define pii pair<int, int>
#define fi first
#define se second
#define ll long long
using namespace std;
int n, s, q, e, bc;
const int N = 105;
const ll M = 1e17;
bool sh[N];
int cel[N][N];
pii c[N];
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
cin >> n >> s >> q >> e;
for(int i=1; i<n; i++)
{
int u, v, w; cin >> u >> v >> w;
cel[u][v] = cel[v][u] = w;
c[i] = {u, v};
}
for(int i=0; i<s; i++)
{
int c; cin >> c;
sh[c] = 1;
}
while(q--)
{
int r; cin >> bc >> r;
bool es = 0, sf = 0, sf2 = 0;
ll sum = 0, sum2 = 0;
for(int i=r; i<=n; i++)
{
if(i == e)
{
es = 1;
break;
}
if(sh[i]) sf = 1;
if(c[bc] == make_pair(i, i+1) ||
c[bc] == make_pair(i+1, i))
break;
if(!sf) sum += cel[i][i+1];
}
for(int i=r; i>=1; i--)
{
if(i == e)
{
es = 1;
break;
}
if(sh[i]) sf2 = 1;
if(c[bc] == make_pair(i, i-1) ||
c[bc] == make_pair(i-1, i))
break;
if(!sf2) sum2 += cel[i][i-1];
}
if(es) cout << "escaped\n";
else if(!sf2 && !sf) cout << "oo\n";
else
{
if(sf && sf2) cout << min(sum, sum2);
else if(sf) cout << sum;
else cout << sum2;
cout << '\n';
}
}
return 0;
}
