#include<bits/stdc++.h>
using namespace std;
#define cIO ios_base::sync_with_stdio(0);cin.tie(0)
#define fileIO(x) ifstream fin(string(x)+".in"); ofstream fout(string(x)+".out")
#define cont(container, object) (container.find(object)!=container.end())
#define sz(x) (int) (x).size()
#define ll long long
#define v vector
const ll INF = LLONG_MAX / 2;
const int max_log = 18;
v<v<pair<int, ll>>> adj;
v<pair<int, ll>> p;
v<v<pair<int, ll>>> c;
v<v<pair<int, ll>>> jmp;
v<v<ll>> jmp_f, jmp_d;//jump 2^k steps to parent & distance
v<ll> ds_subtree;//min dist to store in subtree
v<bool> is_store;
v<int> depth;
v<pair<int, int>> roads_list;
void dfs_p(int node)
{
if (is_store[node]) ds_subtree[node] = 0;
for (auto nxt : adj[node])
if (nxt.first != p[node].first)
{
p[nxt.first] = { node, nxt.second };
c[node].push_back(nxt);
depth[nxt.first] = depth[node] + 1;
dfs_p(nxt.first);
ds_subtree[node] = min(ds_subtree[node], ds_subtree[nxt.first]+nxt.second);
}
return;
}
int main()
{
fileIO("valley");
//remember distances could be long long
int N, S, Q, E; cin >> N >> S >> Q >> E;
adj.resize(N + 1);
is_store.resize(N + 1);
p.resize(N + 1); c.resize(N + 1);
p[E] = { E,0 };
ds_subtree.resize(N + 1, INF);
depth.resize(N + 1);
jmp = v<v<pair<int, ll>>>(N + 1, v<pair<int, ll>>(max_log + 1));
jmp_f = jmp_d = v<v<ll>>(N + 1, v<ll>(max_log + 1, INF));
roads_list.resize(N + 1);
for (int i = 1; i <= N - 1; i++)
{
int a, b; ll c;
cin >> a >> b >> c;
adj[a].push_back({ b,c });
adj[b].push_back({ a,c });
roads_list[i] = { a,b };
}
for (int i = 1; i <= S; i++)
{
int a; cin >> a;
is_store[a] = true;
}
dfs_p(E);
for (int i = 1; i <= N; i++)
{
jmp[i][0] = p[i];
}
for (int dep = 1; dep <= max_log; dep++)
for (int i = 1; i <= N; i++)
{
jmp[i][dep] = { jmp[jmp[i][dep - 1].first][dep - 1].first,
jmp[i][dep - 1].second + jmp[jmp[i][dep - 1].first][dep - 1].second };
}
for (int i = 1; i <= N; i++)
{
jmp_d[i][0] = jmp[i][0].second + ds_subtree[jmp[i][0].first];
}
for (int dep = 1; dep <= max_log; dep++)
for (int i=1; i <= N; i++)
{
jmp_d[i][dep] = min(jmp_d[i][dep - 1],
jmp_d[jmp[i][dep - 1].first][dep - 1] + jmp[i][dep - 1].second);
}
for (int z = 1; z <= Q; z++)
{
int I, R;
cin >> I >> R;
pair<int, int> rem = roads_list[I];
if (depth[rem.first] > depth[rem.second]) swap(rem.first, rem.second);
int top_node = rem.second;
//first check if top_node is not a parent of R
if (depth[R] < depth[top_node])
{
cout << "escaped\n";
continue;
}
int stp = depth[R] - depth[top_node];
int R1 = R;
for (int i = 0; i <= max_log; i++)
{
if (stp & (1 << i))
R1 = jmp[R1][i].first;
}
if (R1!=top_node)
{
cout << "escaped\n";
continue;
}
//we know that top_node is a parent
ll min_cost = ds_subtree[R];
ll cum_jmp_cost = 0;
R1 = R;
for (int i = 0; i <= max_log; i++)
{
if (stp & (1 << i))
{
min_cost = min(min_cost, jmp_d[R1][i] + cum_jmp_cost);
cum_jmp_cost += jmp[R1][i].second;
R1 = jmp[R1][i].first;
}
}
if (min_cost == INF) cout << "oo\n";
else cout << min_cost << "\n";
}
return 0;
}
