#include <bits/stdc++.h>
#define int long long
#define ll long long
#define pi pair<int, int>
#define pl pair<ll, ll>
#define x first
#define y second
const ll inf = 1e18;
const int def = 4e6+1;
using namespace std;
int st1[def], st2[def], lazy1[def], lazy2[def];
void push(int crr, int l, int r){
st1[crr * 2 + 1] += lazy1[crr];
st1[crr * 2 + 2] += lazy1[crr];
st2[crr * 2 + 1] += lazy2[crr];
st2[crr * 2 + 2] += lazy2[crr];
lazy1[crr * 2 + 1] += lazy1[crr];
lazy1[crr * 2 + 2] += lazy1[crr];
lazy2[crr * 2 + 1] += lazy2[crr];
lazy2[crr * 2 + 2] += lazy2[crr];
lazy1[crr] = lazy2[crr] = 0;
}
void update1(int l, int r, int ql, int qr, int crr, int val){
if (qr < l || ql > r)
return;
if (l >= ql && r <= qr){
st1[crr] += val;
lazy1[crr] += val;
return;
}
push(crr, l, r);
int mid = (l + r) / 2;
update1(l, mid, ql, qr, crr * 2 + 1, val);
update1(mid + 1, r, ql, qr, crr * 2 + 2, val);
st1[crr] = min(st1[crr * 2 + 1], st1[crr * 2 + 2]);
st2[crr] = min(st2[crr * 2 + 1], st2[crr * 2 + 2]);
}
void update2(int l, int r, int ql, int qr, int crr, int val){
if (qr < l || ql > r)
return;
if (l >= ql && r <= qr){
st2[crr] += val;
lazy2[crr] += val;
return;
}
push(crr, l, r);
int mid = (l + r) / 2;
update2(l, mid, ql, qr, crr * 2 + 1, val);
update2(mid + 1, r, ql, qr, crr * 2 + 2, val);
st1[crr] = min(st1[crr * 2 + 1], st1[crr * 2 + 2]);
st2[crr] = min(st2[crr * 2 + 1], st2[crr * 2 + 2]);
}
int get1(int l, int r, int ql, int qr, int crr){
if (qr < l || ql > r)
return inf;
if (l >= ql && r <= qr)
return st1[crr];
push(crr, l, r);
int mid = (l + r) / 2;
return min(get1(l, mid, ql, qr, crr * 2 + 1), get1(mid + 1, r, ql, qr, crr * 2 + 2));
}
int get2(int l, int r, int ql, int qr, int crr){
if (qr < l || ql > r)
return inf;
if (l >= ql && r <= qr)
return st2[crr];
push(crr, l, r);
int mid = (l + r) / 2;
return min(get2(l, mid, ql, qr, crr * 2 + 1), get2(mid + 1, r, ql, qr, crr * 2 + 2));
}
void solve(){
int n, s, q, e;
cin >> n >> s >> q >> e;
e--;
vector<pi> E;
vector<vector<pi>> edg(n);
for (int i = 0; i < n - 1; i++){
int u, v, w;
cin >> u >> v >> w;
u--; v--;
edg[u].push_back({v, w});
edg[v].push_back({u, w});
E.push_back({u, v});
}
vector<int> in(n, 0), out(n, 0);
int t = 0;
auto dfs = [&](int u, int pre, auto&& dfs) -> void{
in[u] = t++;
for (auto [v, w] : edg[u]){
if (v == pre)
continue;
dfs(v, u, dfs);
}
out[u] = t - 1;
};
dfs(0, -1, dfs);
auto shop = vector<int>(n, 0);
for (int i = 0; i < s; i++){
int u;
cin >> u;
shop[u - 1] = 1;
}
auto dfs2 = [&](int u, int pre, int dis, auto&& dfs2) -> void{
if (shop[u])
update1(0, n - 1, in[u], in[u], 0, dis);
else
update1(0, n - 1, in[u], in[u], 0, inf);
update2(0, n - 1, in[u], in[u], 0, dis);
for (auto [v, w] : edg[u]){
if (v == pre)
continue;
dfs2(v, u, dis + w, dfs2);
}
};
dfs2(0, -1, 0, dfs2);
vector<vector<pi>> qr(n);
vector<bool> escaped = vector<bool>( q, 0);
for (int i = 0; i < q; i++){
int x, u;
cin >> x >> u;
qr[u - 1].push_back({x - 1, i});
auto [p1, p2] = E[x - 1];
int p = p1;
int dis1 = get2(0, n - 1, in[p1], in[p1], 0);
int dis2 = get2(0, n - 1, in[p2], in[p2], 0);
if (dis2 > dis1)
p = p2;
bool flag1 = (in[e] >= in[p]) && (in[e] <= out[p]);
bool flag2 = (in[u - 1] >= in[p]) && (in[u - 1] <= out[p]);
if (flag1 == flag2)
escaped[i] = 1;
}
vector<int> res(q, inf);
auto reroot = [&](int u, int pre, auto&& reroot) -> void{
// cout << "Root = " << u << ": ";
// for (int i = 0; i < n; i++)
// cout << get2(0, n - 1, i, i, 0) << ' ';
// cout << endl;
for (auto [x, indx] : qr[u]){
auto [p1, p2] = E[x];
int p = p1;
int dis1 = get2(0, n - 1, in[p1], in[p1], 0);
int dis2 = get2(0, n - 1, in[p2], in[p2], 0);
if (dis2 > dis1){
p = p2;
swap(p1, p2);
}
bool flag = (in[u] >= in[p]) && (in[u] <= out[p]);
if (!flag){
if (in[p] > 0)
res[indx] = min(res[indx], get1(0, n - 1, 0, in[p] - 1, 0));
if (out[p] + 1 < n)
res[indx] = min(res[indx], get1(0, n - 1, out[p] + 1, n - 1, 0));
}
else{
p = p2;
res[indx] = get1(0, n - 1, in[p], out[p], 0);
}
}
for (auto [v, w] : edg[u]){
if (v == pre)
continue;
update1(0, n - 1, 0, n - 1, 0, w);
update1(0, n - 1, in[v], out[v], 0, -2 * w);
update2(0, n - 1, 0, n - 1, 0, w);
update2(0, n - 1, in[v], out[v], 0, -2 * w);
reroot(v, u, reroot);
update1(0, n - 1, 0, n - 1, 0, -w);
update1(0, n - 1, in[v], out[v], 0, 2 * w);
update2(0, n - 1, 0, n - 1, 0, -w);
update2(0, n - 1, in[v], out[v], 0, 2 * w);
}
};
reroot(0, -1, reroot);
for (int i = 0; i < q; i++){
if (escaped[i]){
cout << "escaped" << endl;
continue;
}
if (res[i] > 1e15)
cout << "oo" << endl;
else
cout << res[i] << endl;
}
}
/*
*/
main(){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (ifstream("input.txt").good()){
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
int t;
t = 1;
while (t--){
solve();
}
}
