#include <bits/stdc++.h>
#define int long long
#define f first
#define s second
using namespace std;
int inf = 1e18;
int depth[100001], dist[100001], res[100001];
pair<int, int> edge[100001];
vector<bool> store(100001, false);
vector<pair<int, int>> a[100001], query[200001];
vector<int> pos[100001];
vector<int> e, luu;
vector<bool> vst(100001, false);
struct segtree{
int n;
vector<int> tr, lazy;
vector<int> mtr;
segtree(int m){
int n = m;
tr.resize(4*m, 0); //Real
lazy.resize(4*m, inf);
mtr.resize(4*m, 0); //Min segtree
}
void build(int node, int l, int r){
if(l==r){
mtr[node] = dist[e[luu[l]]];
tr[node] = -dist[e[luu[l]]];
}else{
int mid = (l+r)/2;
build(2*node, l, mid);
build(2*node+1, mid+1, r);
mtr[node] = min(mtr[2*node], mtr[2*node+1]);
tr[node] = min(tr[2*node], tr[2*node+1]);
}
}
void propa(int node, int l, int r){
if(lazy[node]!=inf){
int mn = mtr[node];
int d = dist[lazy[node]];
tr[node] = mn - 2*d;
// cout << node << ' ' << l << ' ' << r << ' ' << tr[node] << ' ' << lazy[node] << '\n';
if(l!=r){
if(lazy[2*node]==inf or depth[lazy[2*node]] > depth[lazy[node]]){
lazy[2*node] = lazy[node];
}
if(lazy[2*node+1]==inf or depth[lazy[2*node+1]] > depth[lazy[node]]){
lazy[2*node+1] = lazy[node];
}
}
}
}
void update(int node, int start, int end, int l, int r, int u){
propa(node, start, end);
if(start > r or end < l){
return;
}
if(l<=start and end<=r){
if(lazy[node]==inf or depth[lazy[node]] > depth[u]){
lazy[node] = u;
}
propa(node, start, end);
return;
}
int mid = (start+end)/2;
update(2*node, start, mid, l, r, u);
update(2*node+1, mid+1, end, l, r, u);
tr[node] = min(tr[2*node], tr[2*node+1]);
}
int query(int node, int start, int end, int l, int r){
propa(node, start, end);
if(start>r or end < l){
return inf;
}
if(l<=start and end<=r){
return tr[node];
}
int mid = (start+end)/2;
return min(query(2*node, start, mid, l, r), query(2*node+1, mid+1, end, l, r));
}
};
void dfs(int u){
vst[u] = true;
e.push_back(u);
for (auto [v, w]:a[u]){
if(!vst[v]){
depth[v] = depth[u] +1;
dist[v]=dist[u]+w;
dfs(v);
e.push_back(u);
}
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
e.push_back(-1);
luu.push_back(-1);
int n, s, q, E;
cin >> n >> s >> q >> E;
for (int i = 1;i<n;++i){
int u, v, w;
cin >> u >> v >> w;
edge[i] = {u, v};
a[u].push_back({v, w});
a[v].push_back({u, w});
}
dfs(1);
for (int i =1;i<=s;++i){
int u;
cin >> u;
store[u] = true;
}
int m = e.size()-1;
for (int i = 1;i<=m;++i){
pos[e[i]].push_back(i);
}
for (int i = 1;i<=m;++i){
if(store[e[i]] and pos[e[i]][0]==i){
luu.push_back(i);
}
}
int len = luu.size()-1;
for (int i = 1;i<=m;++i){
// cout << e[i] << ' ';
}
// cout << '\n';
for (int i= 1;i<=len;++i){
// cout << e[luu[i]] << ' ';
}
segtree cay(len);
cay.build(1, 1, len);
for (int j = 1;j<=q;++j){
res[j] = inf;
int i, rr;
cin >> i >> rr;
auto [u, v] = edge[i];
if(depth[u] > depth[v])swap(u, v);
int x = pos[rr][0], y = pos[E][0];
int l = pos[v][0], r = pos[v].back();
if((l<=x and x<=r and (y<l or y>r)) or (l<=y and y<=r and(x<l or x>r))){
query[x].push_back({i, j});
}else{
res[j] = -1;
}
}
stack<int> st;
for (int i = 1;i<=m;++i){
while(!st.empty() and depth[e[st.top()]]>=depth[e[i]]){
st.pop();
}
int dau = 0;
if(st.empty())dau = 1;
else{
dau = upper_bound(luu.begin(), luu.end(), st.top())-luu.begin();
}
int cuoi = upper_bound(luu.begin(), luu.end(), i)-luu.begin()-1;
cay.update(1, 1,len, dau, cuoi, e[i]);
// cout << dau << ' ' << cuoi << '\n';
st.push(i);
for (auto [j, id]:query[i]){
// cout << j << ' ' << id << '\n';
int rr = e[i];
auto [u, v] = edge[j];
if(depth[u] > depth[v])swap(u, v);
int x = pos[rr][0];
int l = pos[v][0], r = pos[v].back();
if(x<l){
dau = 1;
cuoi = upper_bound(luu.begin(), luu.end(), i)-luu.begin()-1;
int sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 1\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
}else if(x>r){
dau = upper_bound(luu.begin(), luu.end(), r)-luu.begin();
cuoi = upper_bound(luu.begin(), luu.end(), i)-luu.begin()-1;
int sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 2\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
dau = 1;
cuoi = lower_bound(luu.begin(), luu.end(), l)-luu.begin()-1;
sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 3\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
}else{
dau = lower_bound(luu.begin(), luu.end(), l)-luu.begin();
cuoi = upper_bound(luu.begin(), luu.end(), i)-luu.begin()-1;
// cout << dau << ' ' << cuoi << " LON\n";
int sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 4\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
}
}
}
cay.build(1, 1, len);
for (int i = 0;i<4*len;++i){
cay.lazy[i] = inf;
}
while(!st.empty()){
st.pop();
}
// return 0;
for (int i = m;i>=1;--i){
while(!st.empty() and depth[e[st.top()]]>=depth[e[i]]){
st.pop();
}
int dau = 0;
int cuoi = 0;
dau = lower_bound(luu.begin(), luu.end(), i)-luu.begin();
if(st.empty())cuoi = len;
else{
cuoi = upper_bound(luu.begin(), luu.end(), st.top())-luu.begin()-1;
}
cay.update(1, 1,len, dau, cuoi, e[i]);
st.push(i);
for (auto [j, id]:query[i]){
// cout << j << ' ' << id << '\n';
int rr = e[i];
auto [u, v] = edge[j];
if(depth[u] > depth[v])swap(u, v);
int x = pos[rr][0];
int l = pos[v][0], r = pos[v].back();
if(x<l){
dau = lower_bound(luu.begin(), luu.end(), i)-luu.begin();
cuoi = lower_bound(luu.begin(), luu.end(), l)-luu.begin()-1;
int sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 1\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
dau = upper_bound(luu.begin(), luu.end(), r)-luu.begin();
cuoi = len;
sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 2\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
}else if(x>r){
dau = lower_bound(luu.begin(), luu.end(), i)-luu.begin();
cuoi = len;
int sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 3\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
}else{
dau = lower_bound(luu.begin(), luu.end(), i)-luu.begin();
cuoi = upper_bound(luu.begin(), luu.end(), r)-luu.begin()-1;
// cout << dau << ' ' << cuoi << " LON\n";
int sol = cay.query(1, 1, len, dau, cuoi);
// cout << sol << " NGU 4\n";
if(sol!=inf)res[id] = min(res[id], dist[rr]+sol);
}
}
}
for (int i = 1;i<=q;++i){
if(res[i]==inf){
cout << "oo\n";
}else if(res[i]==-1){
cout << "escaped\n";
}else cout << res[i] << '\n';
}
}
