#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <array>
#include <string>
#include <algorithm>
#include <cmath>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <iterator>
#include <numeric>
#include <complex>
#include <utility>
#include <random>
#include <cassert>
#include <fstream>
using namespace std;
mt19937 rnd(7069);
/* -------------------- Typedefs -------------------- */
typedef int itn;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef float fl;
typedef long double ld;
/* -------------------- Usings -------------------- */
using vi = vector<int>;
using vll = vector<ll>;
using mii = map<int, int>;
using mll = map<ll, ll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
/* -------------------- Defines -------------------- */
#define ff first
#define ss second
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define mpr make_pair
#define yes cout<<"Yes\n"
#define no cout<<"No\n"
#define all(x) (x).begin(), (x).end()
#define USACO freopen("feast.in", "r", stdin); freopen("feast.out", "w", stdout);
/* -------------------- Constants -------------------- */
const int dx[8] = { -1, 0, 1, 0, -1, -1, 1, 1 };
const int dy[8] = { 0, -1, 0, 1, -1, 1, -1, 1 };
const int MAX = int(2e9 + 5);
const ll MAXL = ll(1e18) + 5ll;
const ll MOD = ll(1000000007);
const ll MOD2 = ll(998244353);
/* -------------------- Functions -------------------- */
void fastio() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
}
void precision(int x) {
cout.setf(ios::fixed | ios::showpoint);
cout.precision(x);
}
ll gcd(ll a, ll b) {
if (a == 0 || b == 0) return(max(a, b));
while (b) {
a %= b;
swap(a, b);
}
return a;
}
ll lcm(ll a, ll b) {
return a / gcd(a, b) * b;
}
ll range_sum(ll a, ll b) {
if (a > b) return 0ll;
ll dif = a - 1, cnt = b - a + 1;
ll ans = ((b - a + 1) * (b - a + 2)) / 2;
ans += ((b - a + 1) * dif);
return ans;
}
string dec_to_bin(ll a) {
string s = "";
for (ll i = a; i > 0; ) {
ll k = i % 2;
i /= 2;
char c = k + 48;
s += c;
}
if (a == 0) {
s = "0";
}
reverse(all(s));
return s;
}
ll bin_to_dec(string s) {
ll num = 0;
for (int i = 0; i < s.size(); i++) {
num *= 2ll;
num += (s[i] - '0');
}
return num;
}
ll factorial_by_mod(ll n, ll mod) {
ll ans = 1;
ll num;
for (ll i = 1; i <= n; ++i) {
num = i % mod;
ans *= num;
ans %= mod;
}
return ans;
}
int isPrime(ll a) {
if (a == 1) return 0;
for (ll i = 2; i * i <= a; i++) {
if (a % i == 0) return 0;
}
return 1;
}
ll binpow(ll a, ll b) {
if (!a) return 0;
ll ans = 1;
while (b) {
if (b & 1) {
ans *= a;
}
b >>= 1;
a *= a;
}
return ans;
}
ll binpow_by_mod(ll a, ll b, ll mod) {
if (!a) return 0;
ll ans = 1;
while (b) {
if (b & 1) {
ans *= a;
ans %= mod;
}
b >>= 1;
a *= a;
a %= mod;
}
return ans;
}
/* -------------------- Solution -------------------- */
const int N = 100005;
int id[N], tin[N], tout[N], till[N], shop[N];
ll t[N * 4], lazy[N * 4], ran[N * 4], dist[N], ans[N];
vi nodes;
vector<pii> edge;
vector<pii> har[N];
vector<pair<int, ll>> g[N];
int n, sz, s, q, e, timer;
void prop(int pos) {
if (!lazy[pos]) return;
t[2 * pos] += lazy[pos];
t[2 * pos + 1] += lazy[pos];
lazy[2 * pos] += lazy[pos];
lazy[2 * pos + 1] += lazy[pos];
lazy[pos] = 0;
}
void bld(int l = 1, int r = n, int pos = 1) {
if (l == r) {
t[pos] = dist[l];
return;
}
int mid = (l + r) / 2;
bld(l, mid, 2 * pos);
bld(mid + 1, r, 2 * pos + 1);
t[pos] = min(t[2 * pos], t[2 * pos + 1]);
}
ll qry(int l, int r, int tl = 1, int tr = n, int pos = 1) {
if (l == tl && r == tr) {
return t[pos];
}
prop(pos);
int mid = (tl + tr) / 2;
if (mid >= r) {
return qry(l, r, tl, mid, 2 * pos);
}
if (mid < l) {
return qry(l, r, mid + 1, tr, 2 * pos + 1);
}
return min(qry(l, mid, tl, mid, 2 * pos), qry(mid + 1, r, mid + 1, tr, 2 * pos + 1));
}
void upd(int l, int r, ll val, int tl = 1, int tr = n, int pos = 1) {
if (r < l) return;
if (l == tl && r == tr) {
t[pos] += val;
lazy[pos] += val;
return;
}
prop(pos);
int mid = (tl + tr) / 2;
if (mid >= r) {
upd(l, r, val, tl, mid, 2 * pos);
}
else if (mid < l) {
upd(l, r, val, mid + 1, tr, 2 * pos + 1);
}
else {
upd(l, mid, val, tl, mid, 2 * pos);
upd(mid + 1, r, val, mid + 1, tr, 2 * pos + 1);
}
t[pos] = min(t[2 * pos], t[2 * pos + 1]);
}
void dfs(int u = e, int p = e, ll w = 0) {
id[u] = ++sz;
tin[u] = ++timer;
dist[id[u]] = MAXL;
if (shop[u]) {
dist[id[u]] = w;
nodes.pub(id[u]);
}
for (auto to : g[u]) {
if (to.ff == p) continue;
dfs(to.ff, u, w + to.ss);
}
tout[u] = ++timer;
till[u] = sz;
}
bool upper(int x, int y) {
return tin[x] <= tin[y] && tout[x] >= tout[y];
}
void dfs1(int u = e, int p = e, ll w = 0) {
int l = id[u], r = till[u];
upd(l, r, -w);
upd(1, l - 1, w);
upd(r + 1, n, w);
for (auto elem : har[u]) {
int edge_ind = elem.ff, ind = elem.ss;
int u1 = edge[edge_ind].ff, u2 = edge[edge_ind].ss;
if (!upper(u2, u)) {
ans[ind] = -1;
continue;
}
if (upper(u2, u)) u1 = u2;
int lx = id[u1], rx = till[u1];
int index1 = lower_bound(all(nodes), lx) - nodes.begin();
int index2 = upper_bound(all(nodes), rx) - nodes.begin() - 1;
if (index1 > index2) {
ans[ind] = MAXL;
continue;
}
ans[ind] = qry(lx, rx);
}
for (auto to : g[u]) {
if (to.ff == p) continue;
dfs1(to.ff, u, to.ss);
}
upd(l, r, w);
upd(1, l - 1, -w);
upd(r + 1, n, -w);
}
void slv() {
cin >> n >> s >> q >> e;
vi vec(s);
for (int i = 0; i < n - 1; ++i) {
int x, y;
ll w;
cin >> x >> y >> w;
edge.pub({ x,y });
g[x].pub({ y,w });
g[y].pub({ x,w });
}
for (int i = 0; i < s; ++i) {
cin >> vec[i];
shop[vec[i]] = 1;
}
dfs();
for (auto& elem : edge) {
if (!upper(elem.ff, elem.ss)) swap(elem.ff, elem.ss);
}
for (int i = 0; i < q; ++i) {
int x, y;
cin >> x >> y;
har[y].pub({ x - 1,i });
}
bld();
dfs1();
for (int i = 0; i < q; ++i) {
if (ans[i] == -1) cout << "escaped";
else if (ans[i] == MAXL) cout << "oo";
else cout << ans[i];
cout << '\n';
}
}
void cs() {
int tstc = 1;
//cin >> tstc;
while (tstc--) {
slv();
}
}
void precalc() {
return;
}
int main() {
fastio();
precalc();
//precision(0);
cs();
return 0;
}
