// Parsa Jokar 2023 https://github.com/phictus/ioi
#pragma GCC optimize("Ofast")
#include <iostream>
#include <limits>
#include <vector>
#include <queue>
#include <cstdint>
using namespace std;
struct Edge
{
int64_t v, u, w;
};
constexpr int64_t maxn = 1000, inf = numeric_limits<int64_t>::max();
int64_t n, s, q, e, currentTime = 0, startTime[maxn + 1], finishTime[maxn + 1], dp[maxn][maxn + 1];
Edge edge[maxn];
vector<int64_t> adj[maxn + 1];
bool hasShop[maxn + 1];
void InitDiscovery(int64_t v = 1, int64_t p = 1)
{
startTime[v] = currentTime++;
for (int64_t i : adj[v])
{
int64_t u = edge[i].v + edge[i].u - v;
if (u != p)
InitDiscovery(u, v);
}
finishTime[v] = currentTime;
}
void InitDp(int64_t discard)
{
queue<int64_t> q;
for (int64_t v = 1; v <= n; v++)
{
if (hasShop[v])
{
dp[discard][v] = 0;
q.push(v);
}
else
dp[discard][v] = inf;
}
while (!q.empty())
{
int64_t v = q.front();
q.pop();
for (int64_t i : adj[v])
{
if (i == discard)
continue;
int64_t u = edge[i].v + edge[i].u - v;
if (dp[discard][u] == inf)
{
dp[discard][u] = dp[discard][v] + edge[i].w;
q.push(u);
}
}
}
}
bool IsAncestor(int64_t v, int64_t u)
{
return startTime[v] <= startTime[u] && finishTime[v] >= finishTime[u];
}
int main()
{
ios_base::sync_with_stdio(false);
cin >> n >> s >> q >> e;
for (int64_t i = 1; i < n; i++)
{
cin >> edge[i].v >> edge[i].u >> edge[i].w;
adj[edge[i].v].push_back(i);
adj[edge[i].u].push_back(i);
}
InitDiscovery();
for (int64_t i = 1; i < n; i++)
{
if (startTime[edge[i].v] > startTime[edge[i].u])
swap(edge[i].v, edge[i].u);
}
for (int64_t i = 1; i <= s; i++)
{
int64_t v;
cin >> v;
hasShop[v] = true;
}
for (int64_t i = 1; i < n; i++)
InitDp(i);
while (q--)
{
int64_t i, v;
cin >> i >> v;
if ((IsAncestor(edge[i].u, v) ^ IsAncestor(edge[i].u, e)) == 0)
cout << "escaped\n";
else
{
if (dp[i][v] == inf)
cout << "oo\n";
else
cout << dp[i][v] << '\n';
}
}
return (0 ^ 0);
}
