// Copyright © 2022 Youngmin Park. All rights reserved.
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpi = vector<pii>;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
using ld = long double;
template <typename T, size_t SZ>
using ar = array<T, SZ>;
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
#define all(v) (v).begin(), (v).end()
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
constexpr int INF = 1e9;
constexpr ll LINF = 1e18;
const ld PI = acos((ld)-1.0);
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T>
constexpr bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <typename T>
constexpr bool ckmax(T &a, const T &b) { return b > a ? a = b, 1 : 0; }
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p)
{
return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v)
{
os << '{';
string sep;
for (const T &x : v)
os << sep << x, sep = ", ";
return os << '}';
}
template <typename T>
ostream &operator<<(ostream &os, const deque<T> &v) {
os << vector<T>(all(v));
return os;
}
template <typename T, typename S, typename C>
ostream &operator<<(ostream &os, priority_queue<T, S, C> pq) {
vector<T> v;
while (sz(pq)) {
v.pb(pq.top());
pq.pop();
}
os << v;
return os;
}
void dbg_out()
{
cerr << "\033[0m" << endl;
}
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T)
{
cerr << ' ' << H;
dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr << "\033[1;35m(" << #__VA_ARGS__ << "):\033[33m", dbg_out(__VA_ARGS__)
#else
#define dbg(...) 42
#endif
inline namespace RecursiveLambda
{
template <typename Fun>
struct y_combinator_result
{
Fun fun_;
template <typename T>
explicit y_combinator_result(T &&fun) : fun_(forward<T>(fun)) {}
template <typename... Args>
decltype(auto) operator()(Args &&...args)
{
return fun_(ref(*this), forward<Args>(args)...);
}
};
template <typename Fun>
decltype(auto) y_combinator(Fun &&fun)
{
return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun));
}
};
inline namespace Range {
class ForwardRange {
int src, dst;
public:
explicit constexpr ForwardRange(const int l, const int r) : src(l), dst(r) {}
explicit constexpr ForwardRange(const int n) : src(0), dst(n) {}
constexpr ForwardRange begin() const { return *this; }
constexpr monostate end() const { return {}; }
constexpr bool operator!=(monostate) const { return src < dst; }
constexpr void operator++() const {}
constexpr int operator*() { return src++; }
};
class BackwardRange {
int src, dst;
public:
explicit constexpr BackwardRange(const int l, const int r) : src(r), dst(l) {}
explicit constexpr BackwardRange(const int n) : src(n), dst(0) {}
constexpr BackwardRange begin() const { return *this; }
constexpr monostate end() const { return {}; }
constexpr bool operator!=(monostate) const { return src > dst; }
constexpr void operator++() const {}
constexpr int operator*() { return --src; }
};
using rep = ForwardRange;
using per = BackwardRange;
};
int n, s, q, e;
constexpr int M = 1e5 + 100, K = 17;
string ESC = "escaped", IMP = "oo";
vpi adj[M];
pii edges[M];
int tin[M], tout[M], timer{};
ll dist[M];
ll dp[M], minDist[M];
int jmp[K][M];
ll jmpDP[K][M];
bitset<M> shop{};
void dfs(int u, int pu) {
tin[u] = timer++;
minDist[u] = (shop[u] ? dist[u] : LINF);
for (auto &[v, w] : adj[u]) {
if (v == pu) continue;
dist[v] = dist[u] + w;
jmp[0][v] = u;
for (int j : rep(1, K)) {
jmp[j][v] = jmp[j - 1][jmp[j - 1][v]];
}
dfs(v, u);
if (minDist[v] < LINF) ckmin(minDist[u], minDist[v]);
}
dp[u] = (minDist[u] < LINF ? minDist[u] - 2 * dist[u] : LINF);
tout[u] = timer - 1;
}
void calc(int u, int pu) {
for (auto &[v, w] : adj[u]) {
if (v == pu) continue;
jmpDP[0][v] = min(dp[v], dp[u]);
for (int j : rep(1, K)) {
jmpDP[j][v] = min(jmpDP[j - 1][v], jmpDP[j - 1][jmp[j - 1][v]]);
}
calc(v, u);
}
}
ll query(int R, int root) {
ll ret = dp[R];
dbg(ret);
int u = R;
for (int i : per(K)) {
int nxt = jmp[i][u];
if (nxt && dist[nxt] >= dist[root]) {
dbg(nxt, i, jmpDP[i][u]);
ckmin(ret, jmpDP[i][u]);
u = nxt;
}
}
return (ret == LINF ? LINF : ret + dist[R]);
}
bool isAnc(int u, int v) {
return tin[u] <= tin[v] && tout[v] <= tout[u];
}
void solve()
{
cin >> n >> s >> q >> e;
for (int i : rep(n - 1)) {
int u, v, w;
cin >> u >> v >> w;
adj[u].pb({v, w}), adj[v].pb({u, w});
edges[i + 1] = {u, v};
}
for (int i : rep(s)) {
int x;
cin >> x;
shop[x] = 1;
}
dfs(e, 0);
calc(e, 0);
for (int i : rep(q)) {
int id, r;
cin >> id >> r;
auto [u, pu] = edges[id];
if (dist[u] < dist[pu]) swap(u, pu);
if (!isAnc(u, r)) {
cout << ESC << '\n';
}else{
ll res = query(r, u);
if (res == LINF) cout << IMP << '\n';
else cout << res << '\n';
}
}
}
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
int testcase = 1;
// cin >> testcase;
while (testcase--)
{
solve();
}
#ifdef LOCAL
cerr << "Time elapsed: " << 1.0 * (double)clock() / CLOCKS_PER_SEC << " s.\n";
#endif
}
